Lawrenceville Landscaping and Lawn Care of Buford Georgia

Growth & Development

Trees, turfgrasses, shrubs, flowers and vines make up the majority of plant types on your grounds. Common aspects of these plants are that they are all highly evolved and that they have similar characteristics of growth and development. Most notably, they are all vascular seed plants, they all conduct photosynthesis, and they all derive nutrients and water from their surroundings.
All seed plants have flowers that are made up of reproductive structures (stamens and pistils) and non-reproductive structures (petals and sepals). Flowers bear the seed that contains the embryo that can develop into a new plant.Three vegetative organs—the root, stem and leaf—are easily recognized. These organs are responsible for extracting
water and nutrients from the soil and transporting  them through a plant, providing plant structure and anchorage, and conducting photosynthesis. Fundamental to an understanding of plant anatomy and function is an understanding of the interrelationship and interdependence of plant parts. Seed plants start as rudimentary embryos and develop roots, leaves and flowers initially in that order. Each plant part develops from undifferentiated cells and becomes a more distinct organ. Consequently, the separation of the plant into discrete,
defined organs is only approximate. You won’t find a line dividing leaves from stems or roots from stems, but you will find a gradual change in cell structure and organization where two organs join.

PLANT CELLS
Plants are made up of many individual basic units called cells. Cells are the smallest biological unit having characteristics of life. They have the ability to extract substances from their environment and continually adapt to their environment; and they have a unique chemical composition, structure, metabolism, growth, reproduction
and organization. Although plant cells differ depending on their function, you can visualize a generalized, undifferentiated, unspecialized plant cell. On the outside of the cell is the primary cell wall, which encloses the cytoplasm in which you find deposits called inclusions (oil and fat droplets, spherosomes, protein bodies, starch grains and crystals) and metabolic bodies called organelles (nucleus, plastids, mitochondria, Golgi bodies and ribosomes). The cytoplasm is a semifluid substance that is pressed against the cell wall by a central vacuole. The vacuole is filled with a watery solution of dissolved inorganic and organic molecules, as well as some insoluble material.

The plasma membrane separates the cytoplasm from the primary cell wall. Another cell membrane, the tonoplast, envelopes the vacuole and separates it from the cytoplasm.
The last generalized plant-cell feature is the plasmodesmata, which are strands that extend through cell walls and connect the cytoplasm of adjoining cells.The organelles in the cytoplasm have distinct functions. Chloroplasts are the bodies in which photosynthesis takes place. The nucleus contains all the genetic material needed for cell reproduction. Respiration takes place in the mitochondria.

PLANT TISSUES
A seed plant is made up of many individual cells, which are cemented together. You will find several different types of cells in plants, and when you group them together as a distinct functional and structural unit, you call them tissue. The major tissues of vascular plants are the dermal, vascular and fundamental (ground) tissues. The dermal tissues (epidermis and periderm) make up the protective structures of a plant. Vascular tissues are a plant’s conducting tissues.  Generalized plant cell showing the complexity of many subcellular bodies surrounded by membranes. Membranes divide the cell into compartments and subcellular bodies. A cell must maintain the integrity of these membranes if it is to survive and function.Peroxisomes Chloroplasts Nucleus Plasma membrane Cell wall MitochondriaVacuoleTonoplast Parenchyma cell. Cell types.Collenchyma cellsSclerenchyma cell  Vascular tissues include the xylem (water conducting) and phloem (food conducting) tissues. Fundamental or ground tissues make up the basic substance of plants and include three distinct types: parenchyma, col-lenchyma and sclerenchyma . Parenchyma cells are living and capable of growth and division. They are responsible for photosynthesis, wound healing, storage and new growth. Collenchyma cells also are living and capable of producing new growth but consist of thick-walled cells and mainly serve as supporting tissue in leaf veins and stems. Sclerenchyma are thick-walled cells that may or may not be living at maturity. Sclerenchyma function
in a structural role and are made up of fibers (slender elongated cells) and sclereids (cells that vary in form from branched to elongated to relatively concentric).

GROWTH AND GROWING POINTS
Growth is defined as the increase in size by cell division or cell enlargement. This increase in size results from the plant taking up air, water and nutrients and incorporating
them into its structure. Light energy is the driving force behind growth. As mentioned above, parenchyma and collenchyma cells are living and capable of dividing to produce new tissue. Tissue that is actively dividing to produce new tissue is called a meristem. Meristems are actually the growing points on a plant Buds on branches of trees or the apical meristem on the top of turfgrass crowns are examples of growing points. Growing points give rise to new leaves, flowers, branches and roots. Keeping these growing points alive and active is the key to growing plants.

ROOTS
Roots are responsible for extracting moisture and nutrients from the soil and anchoring the plant in the soil .  Roots originate from the growing embryo and are the first structure to emerge from the seed during germination.
This first root developing from the embryo is called the primary root, or taproot, and all other roots are called adventitious roots—roots arising from any organ other than the embryo. Roots consist of a growing point at the tip, which is protected by a root cap; the epidermis on the outside of the root; the cortex, which makes up the flesh of the root; root hairs, which absorb moisture and minerals; and the vascular cylinder, which includes the xylem, phloem, cambium and pericycle. Roots add new growth via the growing points at their tips. Roots of most woody species primarily are concentrated in the top 3 feet of soil and can spread two or three times the diameter of the spread of branches, also referred to as the drip line of a tree. But surprisingly, the most active portion of a woody-plant root system is about 6 inches deep and only reaches out to the drip line of the tree. By contrast, the most active zone of grass-root water absorption is only about 1 inch deep.Root systems are broadly divided into either fibrous-root or tap-root systems. Fibrous roots are multibranched and brushlike and are typical of mature grasses and certain trees and shrubs. Taproot systems consist of one main root that grows deep in the soil. Under dry conditions, plants with tap roots are able to extract water from deep in the soil. However, tap-rooted plants are more difficult to transplant because they lack the extensive branching close to the soil surface that fibrous-root systems have. This branching tends to hold the root ball together and produce more small roots for extracting moisture from the soil.

STEMS
Stems are the connecting structures between the leaves and roots. It is through the stem that water and nutrients are transported to the leaves from the roots, and carbohydrates are conducted from the leaves throughout the plant. Stems consist of nodes separated by internodes with buds developing at the nodes. Buds can give rise to leaves, flowers and lateral stems. A shoot is a general term Axillary budDormant budPeridermRoot hairsApical meristem of main shootApical meristemof axillary shootStem withyoung peridermStem withscaly barkTaproot withperidermLateralroot Root capenclosing root apical meristemFigure 3. This illustration shows growing points of a young perennial dicot.Root hairs1 mmCasparian stripCell elongationzoneApical meristemRoot capRegion of cell differentiation1 mmEndodermisCortexEpidermisVascular tissuePericyclePhloemCambiumXylemCortexEpidermisEndodermisRoot hairsCasparian stripFigure 4. Illustration of a root longitudinal section and cross section.

The crown consists of a series of nodes with unelon-gated internodes. The crown is the key to survival of turfgrasses.
Leaves grow from the crown and envelope the growing point. You can cut the leaves off turfgrass plants or injure them, but the plants will live as long as the crowns stay alive.At certain times of the year, turfgrasses produce a flowering culm. A culm originates from the top of the crown, consists of nodes and internodes, and terminates with a flower or florets. Alternately appearing on either side of the crown is a series of axillary buds that give rise to lateral stems, such as tillers, rhizomes and stolons. Lateral stems are elongated stems with nodes and elongated internodes. When the lateral stem grows up within the leaf that lies under the node, it is called a tiller. All grasses produce tillers that generally do not spread far from the mother plant. Some grasses vegetatively spread by tillering alone, and these are called bunch grasses. Perennial ryegrass is an example of a bunch grass. When a lateral stem grows horizontally through the leaf that lies below on the crown, it is called a rhizome or stolon. Rhizomes (see Figure 7, below left) grow horizontally under the ground, may branch or root at nodes and produce a new plant at their tip(s). Stolons are similar to rhizomes but grow on top of the soil. Examples of rhizomatous grasses are Kentucky bluegrass and creeping red fescue. Rough bluegrass and bentgrass are stoloniferous grasses. Some grasses, such as zoysiagrass and bermudagrass, spread by rhizomes, stolons and tillers. It’s important to reinforce the fact that both rhizomatous and stoloniferous grasses also produce tillers, but bunch grasses vegetatively spread only by tillering.

LEAVES
Because the leaf is the chief site of photosynthesis, it is critical that you understand its structure before going on to learn about photosynthesis. The major tissues of a leaf are epidermis, mesophyll and vascular bundles (see  The epidermis is like the skin on a leaf. It is a single layer of cells and is covered with a cuticle—a wax-like layer that seals the leaf from movement of gases and water into and out of the leaf. One peculiar structure of the epidermis is the stomate—the pore through which water and gases, such as carbon dioxide and oxygen, flow into and out of the leaf. The unique geometry of guard cells on either side of the stomate allows them to open and close the stomate in response to fluctuations in their turgor pressure. Stomates generally are open during the day and close at night or when moisture stress occurs. When stomates are open, water can leave the plant in the form of vapor, thus cooling the plant. This water vapor loss is called transpiration. In grasses, leaves are composed of two parts—the blade BladeSheathGrowing pointPrimordial leavesAxillary budAdventitious root#RootsCrownYoung leafThird young leafNext youngest leafPrimary rootYoungest leafInflorescenceCollarFlowering culmFigure 5. This generalized grass exhibits both stoloniferous and rhizomatous growth. Note that it also produces tillers like all grasses. A flowering culm extends from its crown.AuricleLiguleLeaf bladeTillerLeaf sheathStolonRootsRhizomedaughterplantRhizomeStolondaughterplantSenescingleafFigure 6. Generalized turfgrass crown.Mature cataphyllElongating cataphyllElongating internodeGrowing pointOld cataphyllAxillary budNodethat refers to the stem and its associated leaves. In the case of grasses, three types of stems exist: the crown, flowering culm and lateral stems (see Figure 5, above right). The crown is the primary stem of grasses; it is from the crown that leaves, flowering culms and other stems originate (see Figure 6, below). Figure 7. Detail of the tip of a Kentucky-bluegrass rhizome.

and the sheath—that are connected by the collar region (see Figure 9, above). The collar region is especially important in identifying turfgrasses. Structures, such as ligules (a membranous or hairy tissue at the base of the blade), auricles (appendages at the margins of the leaf in the collar region) and collars (the back sides of the leaves in the collar region) may vary among the turfgrasses. FLOWERS Flowers are the reproductive organs of plants. They consist of male and/or female parts (see Figure 10, below). Some plants produce separate male and female flowers, and other plants produce flowers with both male and female parts. Some entire plants are either male or female. This can be important for ornamental species. For example, many fruitless trees are merely male plants. The male flower parts consist of the stamen composed of an anther and a filament. The anther holds the pollen grains, which give rise to sperm. The female portion of the flower is the pistil. It is commonly flask shaped, with a swollen basal portion called the ovary connected to a stalk-like style topped off with a swollen portion at the tip called the stigma. In most cases, pollen must be transferred from the anther to the stigma for the pollen tube to germinate and transfer the sperm to the ovary for fertilization to occur and embryo and seed to develop. One exception occurs in Kentucky bluegrass, where an embryo is developed
in the flower from cell division of the vegetative tissue in the ovule. This process is called apomixis and is the reason why most seeds of Kentucky bluegrasses are genetically identical, like a clone. PLANT PHYSIOLOGYWe mention that light energy is the driving force behind growth, and plants accomplish this through the process of photosynthesis. Photosynthesis involves activation of chlorophyll (the green pigment in leaves) molecules by light combined with the assimilation of carbon from the air as carbon dioxide to form glucose sugar (a carbohydrate). Carbohydrates are the actual food plants rely on for growth. Photosynthesis is actually a combination of two separate
but related processes—a light reaction and a dark reaction In the light reaction, the chlorophyll molecule changes to an excited state when exposed to blue or red light. During this light phase of the reaction, water is split into oxygen (which the plant expels), electrons (which are transferred to produce photochemical energy in the bonds of adenosine triphosphate
[ATP]) and hydrogen ions (which are used to create another high-energy molecule called the reduced form or nicotinomide adensine diphosphate [NADPH]). The high-energy bonds in ATP and NADPH are then used to drive the second reaction called the dark reaction. In the dark reaction, carbon dioxide from the atmosphere
enters the plant through openings— stomates—in the leaves. In most plants, carbon dioxide immediately reacts
with a five-carbon molecule called ribulose-bisphosphate
(RuBP) to form a three-carbon compound called 3-phosphoglycerate (3-PGA) in a reaction catalyzed by the enzyme RuBP carboxylase. Because the first molecule formed after carbon dioxide is fixed is a three-carbon molecule, we call plants with this carbon-fixation system C3 plants. One problem encountered by C3 plants is that the same enzyme that catalyzes the fixation of carbon dioxide from the air also can fix oxygen from the air and lead to photorespiration
 and a net loss of carbon dioxide. Some plants (primarily monocots) have a different way of fixing carbon dioxide from the air. They get around the problems of photorespiration through their unique plant anatomy and additional enzyme systems for fixing carbon dioxide (see Figure 13, at right). In these species, a three-carbon molecule called phosphoenol pyruvate Figure 8. Cross section of a leaf showing the major tissue types: dermal, vascular and fundamental (ground) tissues.Phloem (vascular)Upper epidermis (dermal)Palisadeparenchyma (ground)SclerenchymafibersXylem (vascular)ChloroplastsCuticleIntercellular air spaceStomateVascular bundleSpongyparenchyma (ground)Lower epidermis(dermal)Bundle sheathImage not found on CD for Figure 9.PetalSepalOvaryReceptacleStamenFilamentAntherStamen detailPistil detailStigmaStyleOvaryOvulePistilFigure 10. Flower parts.

(PEP) reacts with carbon dioxide from the air to form a four-carbon molecule called oxaloacetic acid (OAA)—thus the name C4 plants. The enzyme that catalyzes the carbon-dioxide fixation is called PEP carboxylase, and it only fixes carbon dioxide and not oxygen. Eventually OAA is converted to malic acid, which moves out of the cytoplasm—or mesophyll cells—and into the chloroplasts of tightly packed bundle-sheath cells. There the malate splits off a carbon-dioxide molecule, which is picked up by RuBP carboxylase, the same enzyme that fixes carbon
dioxide from the air in C3 plants. Because the RuBP carboxylase is compartmentalized in bundle-sheath cells and not exposed to oxygen in the air, no photorespiration takes place in C4 plants. ATP and NADPH from the light reaction are then used in the next two reactions. Eventually these phosphorylated
sugars transform into glucose, fructose and other simple sugars.Because photorespiration is more of a problem in warmer temperatures, C4 plants tend to be better adapted to warmer climates, where they evolved the C4 process to avoid photorespiration. Further, species that possess the C4 mechanism and anatomy mostly (though not entirely) are monocots, especially grasses and sedges. Therefore, turfgrass scientists have found it useful to distinguish C4 turfgrasses from C3 turfgrasses with the terms warm-season species (C4 plants) and cool-season species (C3 plants). Virtually all trees and shrubs grown in North American landscapes are C3 plants, so the distinction is not as useful in the ornamental industry, where these terms are not used in this regard. Once simple sugars are produced through photosynthesis,
they can be converted to more complex sugars, such as sucrose, starch, fructosans or structural carbohydrates such as cellulose. In the case of cool-season grasses, the primary storage carbohydrate is fructosan—a long chain (2)NADPH(2) ATPATPCO2H2OStarch(2) Triose phosphate(3C)3(3C)(2) 3-phosphoglycerate RuBP carboxylase enzyme(1) Ribulose-1,5-bis-phosphate (5C)Sugar phosphates(2C, 3C, 4C, 5C, 6C, 7C)(1)Hexose phosphate(6C)Ribulose-5-phosphate12Figure 11. The C3 cycle involves three steps: 1) Formation of a CO2 receptor and its incorporation of carbon from CO2 to form two molecules of a three-carbon molecule (thus C3 cycle), 2) production of triose phosphate using the energy from ATP amd NADPH from the light reaction, 3) production of phosphorylated sugars and regeneration of the five-carbon phosphorylated sugar that started the cycle off.WARM-SEASON VS. COOL-SEASON GRASSES WARM-SEASON SPECIES# Optimum temperature: 85° to 105°F# Slow to green in spring# Quick to go dormant in fall because of photodestruction of chlorophyll at temperatures less than 60°F and cold-sensitive enzymes, which fix carbon dioxide from the air# Best growth in summer# Not very cold hardy# No photorespiration and better photo-synthetic efficiency. COOL-SEASON SPECIES# Optimum temperature: 50° to 77°F# Best growth in spring and fall due to cooler temperature and lower photorespiration# Cold hardy# Photorespiration occurs.Air3 phosphoglyerate(3C)Phosphoglycolate(2C)RuBPcarboxylaseenzymeRuBP(5C)O2PhotorespirationFigure 12. Photorespiration. The same enzyme catalyzing the initial reation in the C3 cycle where CO2 is picked up from the air can also pick up oxygen instead. This leads to photorespiration.Oxaloacetate (4C)NADPHPEP carboxylase enzymeMalatePyruvateMalateNADP+CO2C3 CycleCO2BundlesheathcellPyruvateMesophyllcellEpidermisSugarPhosphoenol pyruvateATPFigure 13. Warm-season plants initially pick up CO2 from the air with a different mechanism than cool-season plants. The first product is a four-carbon molecule (thus C4 cycle). The CO2 is then shuttled to another part of the leaf that is protected from the surrounding air. It is here that the CO2 goes through the C3 cycle.Airof fructose with a terminal glucose. Warm-season grasses store sugars as starch. The sugars that the plant stores then are broken down by the plant and used for growth. This process is called respiration. Both plants and animals carry on respiration
and use the same biochemical pathways. Oxygen is required for respiration, and carbon dioxide is expelled (the opposite).

Soils
Soil scientists define soil in various ways, but all definitions illustrate the fact that soil is not as simple as many assume. Soil is the uppermost layer of material covering most of the earth’s land surface
and consists of mineral particles, organic matter, microorganisms, water and air. The possible types and proportions of these components are innumerable, which is why so many different types of soil exist.Soil scientists divide soil into layers they call horizons. The A horizon is the uppermost several inches and consists
mostly of what we know as topsoil. It is often dark in color and rich in organic matter, and it usually provides a favorable environment for plant growth. The next two layers, the B and C horizons, are lighter in color, lower in organic matter and relatively infertile. We call the B and C horizons subsoil. Plant roots generally extend through the A horizon and well into the B horizon. However, the C horizon, which may be well below the surface, is comparatively inhospitable for root growth. In landscape situations, this natural layering often is absent due to soil movement during construction. All too often, this means that no topsoil layer is present, forcing the landscape installer to modify the existing subsoil to make it more favorable to plant growth.Aside from horizons, which describe the position of the soil layer, soil scientists also refer to soil fractions. Fractions
refer to organic or inorganic (mineral) substances. Thus, most soils are composed partly of a mineral fraction and partly of an organic fraction. A few soils are almost completely organic, and others are mostly mineral.• The mineral fraction of soil, consisting of particles that ultimately originated from rock, comprises the largest percentage of most soils. The type of rock from which the mineral particles originated has some bearing on the chemistry of a soil. However, the mix of particle sizes has a greater impact on soil quality and how you must manage it. The age of the soil and how much weathering it has undergone determine particle size: Older, more weathered soils consist of smaller particles. The smallest particles are clay. Larger (but still quite small) particles are silt, and the largest particles (that still qualify as soil) are sand (see table, “Sizes of soil particles,” above right). Soils rarely, if ever, consist of solely one size of particle. Thus, soils are classified according to the proportion of each particle size they contain—we commonly refer to this as soil texture (see Figure 1, at right).Texture, in the broadest sense, is stated as coarse (sandy soils), medium (silts or loamy soils) or fine (clayey soils). Loamy soils are intermediate in nature and not totally dominated by the characteristics of any particular particle
size, though they proportionately contain
more silt than sandy or clayey soils. Thus, there is no such thing as a loam particle,
only loam soils. Loamy soils generally have the best overall characteristics for plant growth. To be even more specific, we combine these terms. For example, sandy clay has significant amounts of sand but is dominated by clay particles and clay characteristics. A sandy loam is a mix of particle sizes not totally dominated
by characteristics of any particle size, but—due to a somewhat higher relative sand content—its qualities tend toward those of sand. Other terms you’ll often encounter
to describe texture include light and heavy, referring
to sandy and clayey soils, respectively. As we’ll see, texture, more than any other single aspect, determines the manageability of soils (see sidebar, “Testing for texture,”
page 9).• Organic matter (OM), the other soil fraction, is present
in most soils, but content varies widely. Soils low in organic matter may have less than 1 percent OM content, whereas highly organic soils range far higher. Most soils contain less than 10 percent, and many—especially in arid climates—hold only 1 or 2 percent OM.OM results from decaying plant material. This decay is brought about mainly by bacteria and fungi that consume plant matter as food. The resulting residues are a rich mix of organic materials that usually have a positive effect on 803020100109080307060405050406070201090sandsandsandyloamloamsandyclay loamloamyclay loamsandyclayclay (40%)siltloamsiltsiltyclay loamsiltyclayclaysilt (40%)sand (45%)Clay separate, %Silt separate, %Sand separate, %201030405080901006070100Figure 1. The “soil triangle” shows the 12 textural classes recognized by the U.S. Department of Agriculture. If you know the percentage of each component present in your soil, you can use the triangle to determine the textural class to which the soil belongs. SIZES OF SOIL PARTICLESParticle typesDiameter (millimeters)GravelAbove 2.00Very coarse sand1.00 to 2.00Coarse sand0.50 to 1.00Medium sand0.25 to 0.50Fine sand0.10 to 0.25Very fine sand0.05 to 0.10Silt0.002 to 0.05ClayBelow 0.002
soil quality. As complex organic molecules break down into simpler forms, the organic matter eventually arrives at a semi-stable form we call humus—the dark-colored substance we commonly associate with “rich” soil.Humus contains a variety of carbohydrates, proteins, lignin, cellulose and other materials, but its main benefit does not lie in its nutritional content (most of which is unavailable to plants). Humus improves the physical structure and chemistry of soils so that they have better
water- and nutrient-holding capacities and greater permeability. Notably, humic acid causes clay particles to aggregate into larger particles that act more like sand than clay. This improves drainage and aeration and so is especially valuable in clay soils. Before plant material undergoes extensive decomposition—that is, before it becomes humus—it still is beneficial to soil because it improves physical structure. As stated above, most of the nutrients in humus are unavailable to plants. Eventually, however, even humus can break down into inorganic compounds by the process of mineralization. At this point, nutrients become available to plants again, and the cycle is completed. The reverse of this process is immobilization, wherein microorganisms assimilate inorganic substances into organic compounds. Both of these processes are ongoing in soil, but the overall trend—not counting plant uptake of nutrients—is always toward mineralization.• Water is present in all soils. Texture has the greatest effect on how much water soil can hold: Finely textured soils hold more water than coarse soils. This is because of how soil particles hold onto water molecules. Water molecules “stick” to soil-particle surfaces by a force called adhesion because they possess positive electrical charges that are attracted to negative electrical charges on the soil particles. Thus, a layer of water surrounds soil particles. Even soils that may seem dry have very small layers of water around each particle (though this water may be unavailable to plants). Sandy soils hold the least amount of water due to low soil-particle surface area. A given volume of clay soil, because of the greater number of particles present, contains a far greater surface area onto which water molecules can cling and so has excellent water retention. • Air is present in the pore spaces between soil particles.
Because water is the other substance that can occupy significant amounts of pore space, air content is determined to a large extent by how wet soil is. The presence of air—particularly oxygen—in pore spaces is as important to most plants as water. Thus, good aeration is an important physical property of soil. Soils that hold a great deal of water are low or lacking in oxygen. That is why plants languish in saturated soils—their roots starve for oxygen.• Living organisms are prevalent in nearly all soils. Bacteria,
fungi, protozoans, nematodes and larger creatures such as earthworms inhabit soils, where they live on decaying plant matter and each other. From a soil-management
standpoint, the main benefit of soil organisms is their role in decomposing organic matter, which we discussed above. Warm, moist conditions favor the activity
of these organisms, so these types of climates favor rapid decomposition of organic matter. However, warm moist climates also favor rapid plant growth, which adds more raw material for the decay process. Thus, the cycling occurs more rapidly and on a larger scale. HOW SOIL TYPE AFFECTS MANAGEMENT• Water movement. Because soil particles are solid, water obviously cannot move through them. Instead, it must move around them. Water’s movement in and through soil depends on the arrangement and size of the soil’s pore spaces—the spaces between soil particles. Due to the random way soil particles pack together, pore spaces vary in size. Some are large and some are small. A “typical” soil may be about 50 percent pore space—25 percent small pore space and 25 percent large pore space. The proportion of soil occupied by pore space is its porosity and varies a great deal among soil types. When water drains through a soil, most of its movement
is through large pores. Coarse-textured soils have more large pore spaces than finely textured soils, and air normally fills these large pores. Larger pores are much better at conducting both air and water through the soil, and that’s why sandy soils have excellent drainage and aeration. The rate at which water can flow through a soil is called hydraulic conductivity. Coarser, sandy soils, with their larger pore sizes, have higher hydraulic conductivity than fine, clay soils, which tend to be lower in oxygen and retain more water.Small pores more often contain water, rather than air. Because clay soils have more small pores and greater water YTESTING FOR TEXTURE You can perform a test that gives you a rough idea of soil texture with a Mason jar. Fill a Mason jar about one-third full of soil. Pack it in and then mark the soil level on the side of the jar. Then add water until the jar is about three-fourths full. Cap the jar and shake it vigorously for several minutes. Then set the jar down and allow the soil particles to settle. After a minute or so, the sand particles will move to the bottom. In a few more minutes, silt will start to settle out, and you will see layering in the sediment in the jar. After an hour or so, the silt will have settled completely, but the clay still will be suspended in the water. Measure the depth of the silt and sand layers and compare them to the original
soil level. This gives you an idea of the percentage of these components present in the soil. Subtract these two values from 100, and the remainder is the percentage of clay. For example, if you measured the packed soil in the jar at 4 inches and, after settling, you had 1 inch of sand and 1 inch of silt in the bottom of the jar, the soil would be 25 percent sand, 25 percent silt and the remainder—50 percent—would be clay.
 retention, they also are more prone to saturation due to heavy rainfall or poorly drained conditions. When water completely occupies all the pore space in soil, the soil is saturated. Saturated soils, as we mentioned, lack oxygen and therefore make poor environments for root growth.However, clay soils have their benefits as well. For example, they hold more available water and nutrients, so plants can last longer between irrigations and fertilizer
applications. Sandy soils hold much less water and nutrients, so plants growing in them are more prone to drought and nutrient deficiency. One reason loamy soils are valuable is that they hold more water than sand, but they do not have the drainage problems of clays.Infiltration rate describes how fast water enters the soil surface. Infiltration is similar to hydraulic conductivity and largely dependent on it. Whenever you apply water to the soil surface at a higher rate than the infiltration rate, you will have puddling or runoff.Because clay soils often require short, light doses of water
to avoid runoff or puddling (and possess low hydraulic conductivity), they are more susceptible to salt buildup. This happens because each time you apply water, you also apply a small amount of dissolved salt along with it. In well-drained soils, you easily can apply enough water so that some of it drains, or leaches, completely through the root zone. This water takes some of the dissolved salt with it, thus reducing the amount to which plant roots are exposed. However, when infiltration rates limit you to small doses of water, you cannot apply enough to leach any out of the root zone. Thus, while water leaves the soil by evapotranspiration, the salt stays behind and slowly accumulates to toxic levels as additional irrigation water brings more. This also illustrates why water quality is an important issue.• Compaction and density. An aspect we have not touched on yet is soil-particle shape. Particles smaller than sand tend to be flattened and plate-like. This tendency is very strong with clay particles, and this has important implications. Clay particles, being flat, can stack tightly together, virtually eliminating any pore spaces between particles. In other words, porosity decreases. This is true with silts as well and is what happens when soils compact
and why compacted soils conduct little water or air. Further, root growth is reduced because pore spaces through which small roots grow do not exist in compacted soil. Moist soil is more prone to compaction because when ample water is present in the soil, the particles can slip and slide past one another, making repositioning into a more compact state easier.Clay particles also can seal, for the same reason. The flattened particles all can be oriented in the same positions—
flat—and form a barrier through which water and air cannot penetrate. That’s why it’s important to score glazed surfaces—such as those created by tree-spades in planting holes—to disrupt this barrier and allow water and air penetration. Sand tends not to compact because, unlike clays, sand particles are not flat. They cannot “stack” in a way that reduces pore space. That is why sand is the preferred medium for high-traffic turf such as golf greens and athletic fields—turf growing on sand is not as prone to the damage that compaction causes. At this point, we should mention pans. Pans are impermeable
layers present below the surface of some soils at varying depth. Hard pans are rock-like while clay pans are softer. Most pans occur naturally, but some cultural practices
can create them. For example, repeated core aeration at the same depth can create a pan layer of highly compacted
soil just below the depth of tine penetration.Pans all cause serious drainage problems in landscapes. They prevent water from draining and so create perched water tables. This not only saturates soil, it also causes salt buildup because salt cannot leach out of the soil. Even if you’re able to manage irrigation well enough to prevent these problems, pans still effectively create a “bottom” to the soil, which may be quite shallow. This can restrict the rooting depth of trees and shrubs.CHEMICAL PROPERTIESSoil chemistry is the interaction of various chemical constituents that takes place among soil particles and in the soil solution—the water retained by soil. The chemical interactions that occur in soil are highly complex, but understanding certain basic concepts will better help you manage turf and ornamentals.• Nutrition. Having discussed water relations, it now is a bit simpler to discuss nutrient-holding capacity. Soils hold onto nutritional elements in a way similar to how they retain water: Positively charged nutrient molecules, cations, are attracted to the negative charges on the soil particles. This is called adsorption. The sites where cations attach to particles are cation-exchange sites (see Figure 2, left). Thus, clay retains more nutrients than coarser soils, just as it holds more water, because of the greater surface area (greater number of cation-exchange sites) to which nutrients can adsorb. The ability to hold cation nutrients is called the cation-exchange capacity (CEC) and is an important characteristic of soils in that it relates to a soil’s ability to retain nutrients and prevent nutrient leaching. Coarse soils have low CECs, while clays and highly organic soils have high CECs. A sand may have a CEC of under 10—a Figure 2. This illustration shows plate-like clay particles. The negative (-) signs indicate negatively charged cation-exchange sites. Cation nutrients, as shown, adsorb to these sites. This is how clay soils act as reservoirs for nutrients.H+CA2+CA2+K+H+CA2+H+H+K+NA+NA+K+H+CA2+H+K+
2004 # TURF & LANDSCAPE DIGEST 11
very low figure. Any CEC above 50 is high, and such soils should be able to hold ample nutrients. • Salinity. Some soils, particularly in arid regions, hold high levels of salt. We discussed earlier how clay soils are more prone to salt buildup, and the same principle applies to arid-region soils. Low rainfall prevents leaching of salts, so they build up in soils. Pan layers, common in arid regions, further inhibit drainage and leaching. Some fertilizers and amendments also can increase salinity.• Soil pH. This is perhaps the single most important aspect of soil chemistry. Strictly speaking, soil pH, or reaction, is a measure of the number of hydrogen ions (H+) present in a solution. In more common terms, it is a measure of alkalinity and acidity. The pH scale runs from 0 to 14. Seven is neutral, 0 is the most highly acidic value possible, and 14 is the most alkaline, or basic, value. Most plants grow best in the range of 6.5 to 7.0, which is acidic, but only slightly. The so-called acid-loving plants prefer lower pH, in the range of 4.0 to 6.0. Under 4.0, few plants are able to survive. Slightly alkaline soil is not harmful to most plants (except acid lovers). In strongly alkaline soils, however, nutrient-availability problems related to pH result. The parent material of soils initially influences soil pH. For example, granite-based soils are acidic and limestone-based soils are alkaline. However, soil pH can change over time. Soils become acidic through natural processes as well as human activities. Rainfall and irrigation control the pH of most soils. In humid climates, such as the Northeastern United States, heavy rainfall percolates through the soil. When it does, it leaches basic ions such as calcium and magnesium and replaces them with acidic ions such as hydrogen and aluminum. In arid regions of the country (less than 20 inches of rain per year), soils tend to become alkaline. Rainfall is not heavy enough to leach basic ions from soils in these areas. Other natural processes that increase soil acidity include
root growth and decay of organic matter by soil microorganisms. Whereas the decay of organic matter gradually will increase acidity, adding sources of organic matter with high pH values (such as some manures and composts) can raise soil pH.Human activities that increase soil acidity include fertilization with ammonium-containing fertilizers and production of industrial by-products such as sulfur dioxide and nitric acid, which ultimately enter the soil via rainfall. Irrigating with water high in bicarbonates gradually increases soil pH and can lead to alkaline conditions.In most cases, changes in soil pH—whether natural processes or human activities cause them—occur slowly. This is due to the tremendous buffering capacity (resistance
to change in pH) of most mineral soils. An exception
to this is high-sand-content soils, where buffering tends to be low, as we’ll discuss below.Nutrient availability varies markedly according to pH. This, in fact, is the main reason why pH is so critical. The best pH for overall nutrient availability is around 6.5, which is one reason why this is an optimal pH for most plants.Calcium, magnesium and potassium are cation nutrients,
meaning they are available to plants in a form with a positive charge. As we discussed earlier, these nutrients adsorb to soil particles, especially clay particles. Soils high in clay or organic matter have high CECs. Thus, these soils act as reservoirs for these nutrients and plants growing in them seldom are deficient in the cation nutrients.Cations do not adsorb permanently to particles. Other compounds that are more strongly attracted to the cation-exchange sites can replace them. This is one way that pH affects nutrient availability. Low-pH soils, by definition, have many of their cation-exchange sites occupied by H+ ions. By default, exchange sites holding H+ ions cannot hold other cations. Therefore, low-pH soils are more likely to be deficient in nutrients such as magnesium, calcium or potassium. If cations are not held by particles, they can leach out of the soil.Soil-solution pH also affects the solubility of other nutrients in the soil. In fact, pH affects the availability of all nutrients one way or another (see Figure 3, above). Therefore, maintaining pH close to the ideal level—6.0 to 7.0 for most plants—is important.Buffering capacity is the ability of soil to resist changes in pH. Soils with a high buffering capacity require a great deal of amendment to alter pH. This is good if the soil already has a desirable pH, but it can be a problem if the soil needs pH modification. Normally, soils high in clay or organic matter (those that have high CECs) have high buffering capacities. Calcareous soils often have high Figure 3. The wider portions of the bars in this graph indicate pH ranges that favor availability of that nutrient. POTASSIUMSULPHURBORONCOPPER AND ZINC0 1 2 3 4 5 6 7 8 9 10 11 12 13 14NUTRIENT AVAILABILITY AND PHSoil pHNITROGENPHOSPHORUSCALCIUMMAGNESIUMIRONMANGANESEMOLYBDENUM
12 TURF & LANDSCAPE DIGEST # 2004 chapter 2
buffering capacities because lime effectively neutralizes acid—a great deal of acidification may be necessary to eliminate the lime before you can realize a significant drop in pH. Conversely, in lime-free soils, acid treatment can drop pH significantly. Soils also can resist upward changes in pH, depending on their composition. Because buffering capacity determines how much amendment it will take to change pH, this is an important characteristic. Soil labs determine buffering capacity and adjust their recommendations according to the buffer pH. AMENDING SOILSLandscape managers commonly manage soils to improve
their physical structure. Doing so entails cultivation and, often, the addition of some organic or inorganic amendment.One of the main reasons we amend and cultivate soil is to alleviate compaction (see “Testing for compaction—
bulk density,” below). Thus, it’s appropriate that this discussion should address preventing compaction as the first step in improving soil structure. Trees commonly suffer from construction activity, which compacts soil to an extent that often can kill the plant. On construction sites, create a zone around trees in which equipment is prohibited. In areas with high foot traffic, take steps to route people along paths that will not affect the root zones of existing ornamentals. The same thing applies to vehicular traffic. Other practices also help reduce or prevent compaction:Do not cultivate when the soil is wet. This can be a very frustrating situation during wet periods because it seemingly takes forever for soil—especially clay—to dry. However, cultivating soil when it’s wet will only destroy soil structure and cause the formation of blocky, hard clods impossible to break up. Keep traffic, including foot traffic, off of wet soil—soil compacts more easily when it’s wet. Improve drainage to speed soil drying and reduce saturation during wet periods. Apply mulch around trees, as far as the drip line if possible.
This will lessen compaction effects on the root zone and improve the soil environment for root growth.• Physical cultivation. Cultivation can take place in a variety of situations and by several means. The easiest and best time to perform cultivation is before the installation of the landscape or turf.If pan layers exist in your soil, now is the time to break them up, because it is nearly impossible to do so after the landscape is established. This may require some heavy-duty equipment but is well worth the trouble because pans can cause you no end of problems. Breaking a pan layer may require the use of a deep-ripper implement. If you cannot do this over the entire landscape, at least use augers or some other method of punching through the pan layer in your tree- and shrub-planting holes. Otherwise,
the plants will sit in a “bathtub.” If you must dig the planting hole deeper than you normally would to accomplish
this, do so. Just be sure to compact the backfill below the root ball to prevent too much settling. In established landscapes, cultivating soil is a more complex matter. To treat compaction problems around trees, several
options exist. Air injection and vertical mulching are techniques finding some use, but they have their drawbacks.
A treatment gaining in popularity that provides excellent results for trees growing in compacted soil is soil replacement with radial trenching. This involves digging a trench starting near the trunk and extending it outward to near the drip line. A recent study of this method used trenches that started 10 feet from the trunk of white oaks and radiated outward. The trenches were 10 feet long, 2 feet deep, 14 inches wide and held about 1 cubic yard. The trenches were refilled with amended soil rich in organic matter. These trenches reversed the decline of trees suffering from highly compacted urban soils by providing a favorable soil environment for the tree roots. Such trenches are easy to dig with a variety of equipment (or even by hand) and so represent a viable method of alleviating compaction around existing trees. Any digging around trees should avoid damaging major roots.Surface mulching around trees also is an effective method of improving soil conditions if the mulch covers
a large enough area. Mulch should extend to the drip line if possible. This produces results more slowly but is perhaps the best long-term strategy for alleviating compaction
around trees.Turf-soil amendment is a different matter. The most common method of cultivating turf soil is through core aeration. This method uses hollow tines that pull soil cores from the turf and deposit them on the surB
TESTING FOR COMPACTION—BULK DENSITYBulk density is a measure of compaction useful for comparing two or more samples from the same type of soil. (It is of little use with different
soil types.) Labs commonly express this value in grams of soil per cubic centimeter (cc).You can determine bulk density by using the excavation method. This involves digging a small hole. Remove the soil and place it on a piece of plastic to save for drying. Dry the soil in an oven for 24 hours at 220°F and then weigh it. The next step is to determine the volume of the hole you excavated. Do this by laying a thin plastic bag in the hole and filling it with water until the water level is flush with the soil surface. Note the volume of water that this requires. You now can determine the bulk density. Divide the weight of the soil by the volume of the hole. For instance 1,170 grams of soil divided by 750 cc (1 fluid ounce equals 29.5 cc) equals 1.56 grams per cc. Most soils fall into the range of 1.4 to 1.7 grams per cc. Values much higher than this may indicate a compaction problem.
face. The resulting holes, though they soon fill in with material, increase air and water penetration to the root zone. In many instances (low- to medium-traffic sites), doing this once or twice a year provides adequate relief from compaction. In high-traffic situations, such as golf courses and athletic fields, turf managers may core-aerate several times a year. Repeated coring at the same depth gradually can create a compacted soil layer. Deep-tine aeration, using much longer tines, reduces this problem. Drills or water jets also are aeration options that avoid the problem of compacted
layers. Many golf-course superintendents use a combination of these aeration techniques.• Amending soil. Cultivation techniques such as aeration help alleviate compaction created by traffic. Often, however,
soil has innate properties that make it difficult to manage. You can improve these soils with amendments that impart more desirable qualities to the soil.# Organic amendments benefit soils in several ways. They increase nutrient- and water-holding capacities and improve
drainage and aeration. In different ways, organic amendments benefit both coarse and fine soils. Because OM increases nutrient and water-holding capacity, it helps counter the drawbacks of sand-based soils. In clay soils, water and nutrient-holding capacities are not usually a concern. However, tilth (the quality that allows you easily to work a soil into a loose state), infiltration and drainage
often are poor in clay soils. These, too, benefit from organic matter, as already discussed. Organic amendments are available in many forms (see table, “Organic amendments,” above right), often as processed wood products. These amendments take some time to decompose to the point where they create actual humus, but they still provide infiltration, drainage and tilth in the meantime. Other common amendments include manure and peat.Wood-based amendments are infamous for their ability to tie up soil nitrogen. Obviously, this can be a problem and may require the addition of supplemental nitrogen to offset this loss. Manure can contain high salt levels, another problem that may be of concern in your situation. See Chapter 10 for more information on the effects of amendments on soil fertility. You will do no harm by adding large amounts of organic
amendments to soil. Thus, there is little danger of overdoing it. A more common problem is adding too little. Often, amounts greater than 50 percent by volume are necessary to achieve significant modification. If you feel you need a more precise idea of how much to add to achieve the desired changes, have a laboratory test your soil.# Inorganic amendments can be quite useful for improving soil quality. The main reason to amend soil with inorganic
amendments is to improve porosity and thus increase water and air permeability of the soil. Therefore, this discussion pertains mainly to clay soils. The best way to improve porosity with inorganic amendments is with coarse amendments. These consist of particles that range in size from sand to fine gravel. Smaller particles do not increase porosity enough to be useful as amendments. Coarse amendments should be of uniform particle size: amendments with a wide mix of particle sizes tend to pack tightly and reduce porosity rather than increase it. For amendments to be effective, the amendment particles
must bridge. That is, they must touch each other so that they create large pore spaces in between. This can require between 50 and 80 percent amendment by volume.
Small amounts of amendment are not very effective because they are too sparse to bridge with one another. Sand is the most commonly used inorganic amendment
due to its low cost and effectiveness. Calcined clay, perhaps most recognized as cat litter, is another effective coarse amendment that also increases CEC. Other amendments
that grounds-care professionals occasionally use include diatomite, zeolite, expanded shale, pumice, blast-furnace slag and sintered fly ash. The latter two materials
are by-products that are available on a regional basis. Perlite and vermiculite are materials used primarily in greenhouse and container culture but have disadvantages in landscape use due to their inability to remain intact under traffic.Gypsum (calcium sulfate) is an amendment professionals
often use to increase infiltration in some types of saline soils. Sodium in saline soils destroys good soil structure by causing clay particles to disperse. This dispersion effectively seals soil to water infiltration and percolation. Gypsum (and lime) displaces sodium, causing clay particles to aggregate (clump together) and create large pore spaces through which water can flow. The displaced sodium is then free to leach through the ORGANIC AMENDMENTSMaterialNitrogen tie-up*CommentsBark, compostedModerateLess nitrogen tie-up than raw bark.Bark, rawHighSevere nitrogen tie-up but improves porosity in heavy soils.CompostLowVariable. Qualities depends on material. Good amentment in all soil textures.ManureLowCan be high in salts.PeatModerateGood acidifier, but relatively
expensive.Rice hullsModerate to highInexpensive. Improves water retntion.SawdustHighSevers nitrogen tie-up. Avoid walnut.* Nitrogen tie-up provides some idications of whether you should add supplemental nitrogen if you use that amendment. High nitrogen tie up may requires you to add as much as 1 pound of nitrogen per 1,000 square feet to avoid nitrogen deficiency in the amended soil.
root zone (with enough water).Incorporating amendments—organic or inorganic—is simply a matter of tilling the material into the soil after
you’ve spread it on the surface. Don’t confuse the term amendment with mulch. Mulch refers to material that remains on the soil surface. Mulches can improve soil by reducing compaction, conserving moisture and decomposing
to increase OM in the surface layer of soil. However, by definition, they are not amendments.You can amend soil in existing turf by core aeration followed
by topdressing that you drag into coring holes. This type of soil replacement is not difficult but requires some time—perhaps a year or two depending on frequency of aeration—to achieve significant replacement of soil. # Topsoil. Many times, it is simply more efficient to bring in high-quality soil than to modify the poor soils already present on a site. Though this use of topsoil does not, strictly speaking, make it an amendment, the idea is the same: Provide a good soil environment for plant growth. Topsoil for sale often is actually loam. It may be of excellent quality, but it is a misnomer to call it topsoil. Of course, it is wise to inspect topsoil before purchasing it to ensure it’s of the quality you’re looking for. Ideally, the soil should be reasonably weed-free and should not contain too many large clods.If the difference between the topsoil and the site soil is great—as it usually is—till a shallow layer of the topsoil
into the top few inches of site soil. This will create a transition zone that will aid water movement and root growth between the two soils.CHANGING PHAfter improving porosity, changing pH is the most common reason for altering soils. Raising and lowering pH both are necessary at times, depending, of course, on the pH with which you’re starting.• Reducing acidity. Liming is the practice of applying an agent to reduce soil acidity (raise pH) and make soils more favorable for plant growth. The amount of lime you must add depends on the degree of soil acidity, the buffering capacity of the soil, the desired pH, and the quality and type of lime you use.# Liming materials. The most widely used liming materials
for turfgrass areas consist of carbonates of calcium or magnesium. These include ground, pelletized and flowable limestone. Of these three, ground limestone is the type used most widely. Crystalline calcium carbonate
(CaCO3), one type of ground limestone, is termed calcitic limestone. Dolomitic limestone, another ground-limestone product, comes from ground rock containing calcium-magnesium carbonate (CaMg[CO3]2) and has a higher neutralizing value than calcitic limestone. Dolomitic
limestone not only lowers pH but also can supply magnesium in soils that are deficient. Although ground limestone is the most inexpensive source, it is dusty and not as easy to spread as the pelletized form.Pelletized limestone is ground limestone (either calcitic or dolomitic) that has been aggregated into larger particles
to facilitate spreading and reduce dust. The pellets quickly disintegrate when wet.Flowable limestone is available for use on turf when you need to use a liquid application. Although liquid applications
are dust-free and uniform, you only can apply relatively small amounts at one time, and lime-spray suspensions may be abrasive to sprayer parts.Hydrated (slaked) lime [calcium hydroxide, Ca(OH)2] and burned lime (quicklime—calcium oxide, CaO) provide
a rapid pH change but can be phytotoxic. These products are corrosive and difficult to handle.As you might expect, sources of limestone vary in quality and effectiveness. Even two pelletized limestones made by different companies may vary in their ability to neutralize soil. To get the best bargain when purchasing lime products, look for quality, not just the lowest price. Two main factors govern the quality of a liming material: purity and fineness.# Purity. Most lime recommendations assume you will use liming materials that have the same neutralizing potential
as pure calcium carbonate. In other words, if your soil-test report recommends that you apply 50 pounds of limestone per 1,000 square feet, it assumes you will use a lime source that will raise soil pH to the same extent as 50 pounds of pure calcium carbonate at the same rate. A liming material with the same neutralizing potential as pure calcium carbonate has a calcium carbonate equivalent (CCE) of 100 percent.You should adjust the recommended rate of any liming
material with a CCE of less than or greater than 100 TCALCIUM CARBONATE EQUIVALENT (CCE) AND LIMING RATESTo adjust the lab-recommeneded liming rate for CCE, divide the recommended
liming rate by the CCE of the material you're using (most products state the CCE on their label). Then multiply by 100 to obtain the actual rate you should use. For example:75 pounds of limestone per 1,000 sq. ft. (the label-recommended rate) x 100 = 94 pounds of limestone80 (the CCE of the product) per 1, 000 square feetAs you can see, adjusting for CCE can make a significant difference in rates and helps ensure you are using adequate product to achieve the desired change in pH.
percent (see “CCE of liming materials,” above) so that you apply the right amount of material to raise your soil pH to the target level (see “Calcium carbonate equivalent [CCE] and liming rates,” page 14). Generally, because of impurities such as clay, the neutralizing value of most agricultural limestones is 90 to 98 percent. Most states require that agricultural liming materials state their CCE on the label. # Fineness. Any effective liming material should be finely ground. This is important because the rate at which limestone raises pH increases with the fineness of the particles. Plus, limestone affects only the small volume of soil surrounding each limestone particle. A given volume of limestone contains more particles if it is finely ground and thus affects more soil than coarser limestone. Many states govern the sizes of limestone particles in pelletized lime and agricultural ground limestone. Manufacturers usually print the actual range of particle sizes on the label. However, you will generally find little advantage in using material much finer than these minimum standards.# How and when to apply limestone. Lime will neutralize soil acidity and benefit turf growth faster if you incorporate
it directly into the soil. You can incorporate lime by spreading a layer on the soil surface following a rough grading, then mixing the lime 4 to 6 inches into the soil with rotary tilling equipment. Not only does this practice distribute the lime throughout the entire root zone, you can apply much more in a single application than with a surface application. Often, you can supply the entire lime requirement in a single application during establishment, whereas several surface applications may be necessary on established turf or landscape beds.A means of incorporating lime in established turf is through core aeration. If your soil-test report indicates that an area about to undergo renovation requires liming,
apply the recommended amount of lime (along with any needed phosphorus and potassium) after herbicide treatment and thatch removal, and just before or just after aeration. As you aerate and drag the area, some of the lime/soil mix will fall into the aeration holes and some will remain on the soil surface. The more vigorous
the aeration treatment the better the lime will mix with the soil. Established turfgrass areas should not receive more than 25 to 50 pounds of limestone per 1,000 square feet in any single surface application. If you use hydrated or burned lime, apply no more that 25 pounds per 1,000 square feet in a single application. The main reason for this is to ensure that a layer of excess residue does not remain on or near the surface after watering or, in the case of hydrated or burned lime, that plant injury does not occur. If a soil requires more limestone than you can apply at one time, use semiannual applications until you meet the requirement.Ground limestone sometimes is difficult to spread with conventional spreaders. However, pelletized limestone
spreads easily with conventional drop or broadcast spreaders. For large areas, commercial spreader trucks are available for custom spreading. You can apply ground limestone anytime during the year, but it is most effective in the fall or winter because rain, snow and frost heaving help work limestone into the soil.• Lowering soil pH—acidification. Soils often need acidification
in semiarid and arid regions or when you’ve applied excess lime. Plus, golf-course superintendents sometimes apply acidifying materials to their greens as a means of managing certain diseases. They accomplish this by applying ammonium-containing fertilizers such as ammonium sulfate or elemental sulfur, or by injecting sulfuric acid into their irrigation systems.Ammonium-containing fertilizers are effective for lowering
soil pH when you need only slight acidification over an extended period. In the Northeastern United States, some golf-course superintendents use ammonium sulfate to lower the pH of putting greens affected by take-all patch and summer patch diseases. While this practice is effective in some cases, take care to avoid foliar burn and over-stimulation of turf with nitrogen. To avoid burning, make the applications during cool weather (spring and fall) at low rates. When using this approach for disease management, you should monitor soil-pH levels frequently to avoid nutrition and thatch problems caused by low pH.If you require greater and more rapid acidification, you can use high-sulfur-content products. When you apply sulfur to soil, soil-borne bacteria convert it to sulfuric acid, thereby lowering soil pH. Powdered elemental sulfur
typically is yellow and fairly pure (greater than 90 percent sulfur). As with lime, sulfur is more effective in a finely ground state. Several sulfur products are available in powder form but, as such, are dusty and not easy to apply with spreaders. You also can obtain sulfur in pelletized
form (90 percent powdered sulfur and 10 percent bentonite clay). This is easy to spread with conventional fertilizer spreaders and quickly breaks down into the powdered form when moist. If you want to apply sulfur as a liquid, flowable forms also are available.The best time to apply sulfur is before establishment. By applying sulfur directly to the soil surface, and then tilling it into the soil, sulfur will be in direct contact with soil microbes and distributed throughout the CCE OF LIMING MATERIALS*MaterialNeutralizing valueBurned lime (quicklime)—CaO179Hydrated lime—Ca(OH)2136Dolomitic limestone—CaMg(CO3)2109Calcitic limestone—CaCO3100* These values are for the pure forms of these materials. Actual CCEs of the marketed materials is usually lower due to impurites such as clay.
Incorporating sulfurbefore planting also allows you to use greater amounts than possible with surface applications on established turf.Generally, sandy
soils require smaller amounts of sulfur to lower pH than mineral soils. For example, lowering the pH of a 6-inch-deep layer of sandy soil from 8.0 to 6.5 requires 27.5 pounds of sulfur per 1,000 square feet. However, a clay soil needs 45.9 pounds of sulfur per 1,000 square feet for the same adjustment.Established turf generally requires frequent applications
of sulfur at relatively low rates to lower pH. On putting greens, applications normally are around 0.5 pound sulfur per 1,000 square feet and should not exceed about 2.3 pounds per 1,000 square feet per year. You can double these rates on high-cut turf if you apply the product in cool weather. Remember, excessive sulfur can injure turf, especially in hot and humid weather.To determine if your sulfur applications are having the desired effect on pH, monitor your soil with laboratory tests. Make sure that you test the surface soil (upper 0.5 to 1 inch) separately because most of the sulfur you apply
to established turf will remain and react near the soil surface. This possibly can create highly acidic conditions in the top 0.5 to 1 inch of the soil.In recent years, some golf courses in the Southwestern United States have used sulfuric-acid irrigation-system injections to acidify soil. At least one system uses pH electrodes
and a computer to maintain water pH at a constant 6.5. If the pH falls outside the operating range, the system automatically shuts down. With innovations such as these, acidification of soils with acid injection undoubtedly will become more common in the near future.PH TESTINGYou can determine soil pH with one of several types of soil tests. However, not all soil tests provide accurate information about how much lime or acidifier you should apply. Test kits using dyes, pH pens or pH paper determine
pH rapidly in the field. The least accurate means of determining soil pH is with pH paper, but it can be useful in obtaining an approximate value. While each of these tests can provide a fair indication of soil pH and tell you if you need lime, they do not provide accurate information on how much lime you should apply. The table at left gives amounts of material needed to raise and lower pH. These figures are only approximate—consult a soil lab before undertaking pH modifications.Commercial and university testing labs accurately determine
pH values for soils over a range of pH values. They also provide meaningful lime recommendations for acid soils. They base their lime recommendation on a lime-requirement test that tells you how much lime is necessary to bring the soil to an optimum pH. The lime-requirement test takes the buffering capacity of a soil into account to provide buffer pH. Regarding pH amendments, buffer pH is more important than active pH.Each lab bases its lime recommendations on what they consider to be optimal pH for the turf or ornamentals you’re growing. Before submitting your soil samples, realize
that differences exist among labs regarding what they consider to be the optimum pH ranges for turfgrasses and ornamentals. This is why lime recommendations vary from one lab to another. The best way to deal with this problem is to choose a lab that provides recommendations that make sense to you and then stick with that lab for future testing to maintain consistency. TESTING, SAMPLING AND SOIL LABORATORIESSoil laboratories are necessary to provide accurate analysis
and meaningful recommendations. Many kits and test methods—some of which we mentioned earlier—are available that allow you to conduct crude analyses for various nutrients, as well as pH, texture, density and other factors. However, you should consider these only rough indicators of soil quality. A laboratory analysis is necessary for you to get a good grasp of your soil’s condition.For small landscapes, the cost of testing may not be justified unless serious problems are occurring. However, for larger landscapes and golf courses, the cost of testing is trivial compared to the benefits. The information labs provide allows you to take the appropriate management steps to maximize plant growth. Otherwise, you’re just guessing at how much and what type of material to apply if you wish to amend soils.The results from any kit or lab are only as good as the sample taken. Therefore, ensure that you follow instructions
on the soil-test form. Pay particular attention to the suggested number of subsamples per unit area, sampling pattern, sampling depth, mixing procedure and whether to include thatch as part of the sample. Take care not to contaminate the sample with fertilizer, lime or any other substance that may influence results.TLDRAISING SOIL PHPounds of ground or dolomitic limestone needed per 1,000 square feet to raise pH to 6.5.Starting pHSoil testure classSandLoamClay6.02035505.545751005.0651101504.580150200LOWERING SOIL PHPounds of elemental sulfur needed per 1,000 square feet to lower pH to 6.58.535 to 45N/A45 to 608.025 to 3535 to 507.510 to 1520 to 25

The Turfgrasses
Grasses belong to one of the most evolutionarily advanced families of plants called Poaceae. The Poaceae family is subdivided into six subfamilies that include 25 tribes, 600 genera and 7,500 species. Nevertheless, only a few dozen species are suitable as turfgrasses because they must form uniform soil coverage and tolerate mowing and traffic associated with turf use. One key characteristic
of these grasses that makes them suitable as turfgrasses
is their compressed crown. This enables you to mow without cutting off the growing point and killing the plant. See “Taxonomy of turfgrasses” (page 20) for a list of grasses suitable for turf. Of the three subfamilies that turfgrasses fall into, the Festucoideae subfamily is comprised of cool-season turfgrasses,
and Panicoideae and Eragrostoideae include the warm-season turfgrasses. Differences in temperature-related turfgrass physiology, discussed in Chapter 1, primarily influence adaptation of the turfgrasses. Warm-season turfgrasses are best adapted to southern climates, and cool-season turfgrasses are best adapted to northern conditions (see Figure 1, below). Drought tolerance and avoidance also influence adaptation on non-irrigated sites. Because of these differences in adaptation, no one turfgrass
species will perform well in all locations. You must consider which species and cultivars are best for your particular location. Your local cooperative-extension service can supply you with a list of turfgrasses that are best adapted to your site conditions. Seed suppliers also can assist you in determining the best turfgrasses for your site. COOL-SEASON TURFGRASSES# Fescues. Fescues can be broadly divided by their leaf texture: fine-leaved fescues (creeping red fescue, sheep fescue, Chewings fescue and hard fescue) and tall fescue. Fine-leaved fescues are best adapted to well-drained, low-fertility, low-pH soil and shade. They do not take heat very well and do best when not overfertilized. You will see fine-leaved fescues in mixes with Kentucky bluegrass and perennial ryegrass in cooler climates and in mixes with perennial ryegrass for winter overseeding of warm-season turfgrasses. Of the fine-leaved fescues, only creeping
red fescue is rhizomatous. The rest are bunch grasses. Tall fescue is a relatively coarse-leaved, bunch-type turfgrass that is best adapted to the transitional climatic zone between North and South. Tall fescue is adapted to a wide range of soil conditions and, among cool-season species, tolerates heat and drought well. Because of its coarse-leaf texture, it is best planted alone without being mixed with other more narrow-leaved species. # Bluegrasses. Kentucky bluegrass is the most widely used turfgrass in cool, temperate regions. Its medium leaf texture and dark color make it an attractive turf for lawns. It is rhizomatous, a good sod-former and recuperates
well from injury. Kentucky bluegrass responds well Figure 1. Climatic zones of turfgrass adaptation.SOUTHERN ZONENORTHERN ZONETRANSITIONAL ZONE
o fertilization and will persist in transitional areas when irrigated. One concern of Kentucky bluegrass is its susceptibility
to summer patch, a lethal disease that is difficult
to control. Some cultivars are more resistant to summer patch than others. More than 100 cultivars of Kentucky bluegrass are available to consumers. These cultivars can differ dramatically in color, disease tolerance,
fertility requirement and shade tolerance. Because of this variability, it is extremely important to obtain local recommendations for the best cultivars for your site. Annual bluegrass is a light apple-green-colored blueChlorideae
tribe
Cynodon genus, bermudagrass
C. dactylon
common bermudagrass
C. bradleyi
Bradley bermudagrass
C. magennisii
Magennis bermudagrass
C. transvaalensis
African bermudagrass
Buchloë genus, buffalograss
B. dactyloides
buffalograss
Bouteloua genus, gramagrass
B. gracilis
blue grama
B. curtipendula
sideoats grama
Zoysia genus, zoysiagrass
Z. japonica
Japanese lawngrass
Z. matrella
manilagrass
Z. tenuifolia
mascarenegrassFestucoideae subfamilyAveneae tribe
Agrostis genus, bentgrasses
A. palustris
creeping bentgrass
A. capillaris
colonial bentgrass
A. canina
velvet bentgrass
A. alba
redtop
Phleum genus, timothy
P. pratense
common timothyTriticeae tribe
Agropyron genus, wheatgrasses
A. cristatum
crested wheatgrassPoaceae familyEragrostoideae subfamilyTAXONOMY OF TURFGRASSESPaniceae tribe
Axonopus genus, carpetgrass
A. affinis
common carpetgrass
A. compressus
tropical carpetgrass
Paspalum genus, bahiagrass/paspalum
P. notatum
bahiagrass
P. vaginatum
seashore paspalum
Pennisetum genus, kikuyugrass
P. clandestinum
kikuyugrass
Stenotaphrum genus, St. Augustinegrass
S. secondatum
St. AugustinegrassPanicoideaesubfamilyAndropogoneae tribe
Eremochloa genus, centipedgrass
E. ophiuroides
centipedegrassFestuceae tribe
Festuca genus, fescues
F. rubra rubra
creeping red fescue
F. rubra commutata
Chewings fescue
F. ovina
sheep fescue
F. longifolia
hard fescue
F. arundinacea
tall fescue
F. elatior
meadow fescue
Poa genus, bluegrasses
P. pratensis
Kentucky bluegrass
P. compressa
Canada bluegrass
P. trivialis
rough bluegrass
P. annua
annual bluegrass
Lolium genus, ryegrasses
L. perenne
perennial ryegrass
L. multiflorum
annual ryegrass
Bromus genus, bromegrasses
B. inermis
smooth bromegrass
Cynosurus genus, dogtail
C. cristatus
crested dogtail
Puccinellia genus, alkaligrass
P. distans
weeping alkaligrass
P. airoides
Nutall alkaligrass
P. lemmoni
Lemmon alkaligrass

grass that seeds profusely at very low mowing heights. Primarily a bunch-type winter annual (one type is weakly stoloniferous and is more perennial), it tolerates low mowing and can quickly invade bentgrass greens. Because of its light-green color and the seed heads it produces, it can be a serious weed in bentgrass greens. Annual bluegrass is generally not planted intentionally but will naturally invade well-watered sites. It does not tolerate drought and is prone to many diseases. Because of its pernicious nature, turf managers often give up on keeping it out of turf and end up managing it as a desirable
species. Turfgrass breeders currently are developing commercially viable annual-bluegrass varieties.Rough bluegrass is another light apple-green-colored bluegrass. It is stoloniferous and well adapted to damp, fertile, shaded sites. Rough bluegrass has poor heat and drought tolerance. Because of its stoloniferous growth habit, it tends to segregate itself in patches if mixed with Kentucky bluegrass. Rough bluegrass tolerates cold temperatures
well and is used as an overseeded species in warm-season turfgrass stands. # Ryegrasses. Both perennial and annual ryegrasses are available for turf. Perennial ryegrass is a medium- textured
turfgrass adapted to moderate temperatures. It germinates quickly (within a week) and is most commonly
used as a nurse grass in mixes with slower growing
species such as Kentucky bluegrass and for winter-overseeding in warm-season species. It has good wear resistance, and, coupled with quick germination, it makes a good species for athletic-field turf mixes. One lethal disease that perennial ryegrass is particularly susceptible to is Pythium blight. Annual ryegrass is a cool-season, annual bunch grass with coarse-textured leaves. Although it germinates quickly and its seed is inexpensive, it does not persist. # Bentgrasses. Creeping bentgrass is a fine-textured stoloniferous turfgrass that tolerates low mowing heights. Its aggressive stoloniferous growth habit provides it with excellent recuperative potential but also makes it unsuitable
in mixtures with other species. Creeping bentgrass requires a high level of maintenance (fertility, mowing and disease control) to maintain it as a lawn. It is most used on golf-course greens, tees and fairways as well as tennis courts and bowling greens. Colonial bentgrass is fine-textured and sometimes has weak rhizomes and stolons. It can’t be mowed as short as creeping bentgrass but is suitable for fairway turf. Like creeping bentgrass, colonial bentgrass requires a high level of maintenance. Its poor heat tolerance limits its use to cooler, maritime climates. Velvet bentgrass is the finest-textured turfgrass we use. It is stoloniferous and lighter green in color and is especially
tolerant of shade and acidic soil. Because it has poor tolerance of heat and drought, it is only found in cooler maritime climates of the Northeast and Northwest. Redtop is a coarse-textured, rhizomatous bentgrass that was once used extensively in seed mixtures because of its rapid establishment rate. Unfortunately, redtop persists in newly established turf and, because of its coarse texture,
it is not compatible with fine- or medium-textured turfgrasses. Although not used for fine-turf areas, it is still used in some roadside utility mixes.WARM-SEASON TURFGRASSES# Bermudagrasses. Bermudagrass is the most important and widely adapted warm-season turfgrass. It is a highly variable turfgrass that produces aggressive rhizomes and stolons. Although primarily propagated vegetatively, improved seeded varieties are becoming available. Bermudagrass
thrives in warm, tropical and subtropical climates with moderate to heavy rainfall. Salt tolerance is high. Hybrids developed from crosses between C. dactylon
and C. transvaalensis for golf-course use include Tifgreen,
Tifdwarf and Tifway, and for home lawns, Midiron,
in areas that previously have been too cold for bermudagrass adaptation. # Buffalograss. Buffalograss is one of the few turfgrasses
native to the United Sates. Also unique about buffalograss among the turfgrasses is the fact that it has separate male and female plants. Buffalograss is a fine-textured, light green, stoloniferous grass that is well-adapted to unirrigated sites with low fertility. # Zoysiagrasses. Zoysiagrass is a stoloniferous and rhizomatous
species used for lawns and golf-course fairways in the South and the transition zone. It is not as aggressive as bermudagrass but forms a dense turf that is prone to thatch buildup. Zoysiagrass withstands cold temperatures better than other warm-season turfgrasses. Japanese lawngrass, a medium-textured turfgrass, is the most cold-tolerant zoysiagrass but, like all warm-season turfgrasses,
greens up relatively late in the spring and goes dormant
earlier in the fall than cool-season species. ManiTAXONOMY
OF KENTUCKY BLUEGRASS Kingdom—Plantae, plant kingdom Division—Anthophyta, flowering plants Class—Monocotyledoneae, monocots Subclass—Commelinidae, having chaffy flowers Order—Cyperales, grasses and sedges Family—Poaceae, grasses Tribe—Festuceae, fescue tribe Genus—Poa, bluegrasses Species—pratensis, having rhizomes Cultivar—‘Haga’
chapter 3lagrass is finer-textured but lacks the cold tolerance exhibited
by Japanese lawngrass. # St. Augustinegrass. St. Augustinegrass is a coarse-textured,
stoloniferous grass that is commonly used for lawns in coastal areas of the deep South. It has poor cold tolerance but tolerates moderate shade better than most warm-season turfgrasses. Salt tolerance is good with St. Augustinegrass, but it does not tolerate traffic or compacted
soil. Vegetative propagation is the only means of establishing this species. Several diseases are a problem with St. Augustinegrass. Perhaps the most serious problems are with brown patch, take-all patch and gray leaf spot. St. Augustine decline virus is another serious problem of St. Augustinegrass with no chemical controls available. Resistant varieties include Floratam, Seville and Raleigh. # Paspalums. Bahiagrass is coarse-textured and has short, almost woody rhizomes and stolons. It’s propagated
from seed or sod and is primarily used as a utility
grass on highway roadsides and low-maintenance lawns. It performs relatively well in poorly drained, low-fertility soils. Mole crickets are a serious problem in bahiagrass. Seashore paspalum is another species within the Paspalum genus. Its primary use is for its high salt tolerance.
# Carpetgrass. Carpetgrass is a coarse-textured, low-growing, stoloniferous grass that forms a dense turf capable of crowding out other species. This species is native to the Gulf states and is adapted to other tropical
areas. It’s primarily used on roadsides, airports, golf-course roughs and other utility-turf areas. Its frequent and prolonged production of seedheads is aesthetically objectionable and restricts its use to utility
turf. # Centipedegrass. Centipedegrass is a coarse-textured, slow-growing, stoloniferous species. It is established from sod, sprigs and seeding. It is a true low-maintenance turfgrass. Because of its slow growth, it requires less mowing than bermudagrass or St. Augustinegrass. It also performs well with only one annual application of nitrogen at 1 pound per 1,000 square feet. Traffic tolerance is poor, and it is unsuitable as an athletic-field turf. Centipedegrass typically has a natural yellow-green color and is used as a lawn and utility turf.

Turf Establishment and Renovation
Turfgrass maintenance problems often result from poor planning in the initial stages of establishment. Poor drainage, scalping and turf-susceptibility to environmental
stresses may be the consequence of poor establishment
techniques. To ensure a healthy turf and avoid later maintenance problems, begin with proper site preparation.The primary objectives of soil preparation are:• To provide a firm, smooth surface for rapid establishment
• To provide a rooting medium conducive to water infiltration,
aeration and drainage.The goal of proper site preparation is to create a firm foundation on which you can establish and maintain a high-quality turf with a minimum of difficulty.The steps for preparing the site are the same whether you establish turf by seed or vegetative methods.• Clear the site. Begin by removing any obstructions that may impede turf establishment and make future maintenance
difficult. These include rocks, boulders, old building foundations, roots of dead trees, brush and weeds. When planted over shallow rock outcrops, boulders
or old foundations, the turf will have a restricted root system, and it will continually suffer from drought stress. Either remove the obstructions or bury them at least 15 inches deep.Trees can excessively shade a site. This may prevent good turf establishment and lead to turf thinning. Trees also may reduce air circulation and create an environment
conducive to disease development. So selectively prune tree limbs to let in light and promote air movement
before establishing turf.Trees and turf also compete for nutrients and water. In some cases, you may have to remove trees that interfere with the turf and the site’s planned uses. If so, be sure to remove stumps. Don’t simply bury them. As they decompose,
the soil will sink. Eventually, a depression will form at the site. Fairy-ring disease also is likely to develop
on the excess organic debris. If you don’t remove difficult-to-control weeds from the site before establishment, you can expect serious persistent problems in the turf. Propagules—seeds, rhizomes,
stolons—let the weeds survive tillage and later infest turf. You’ll especially have problems from annual bluegrass seed, quackgrass rhizomes, bermudagrass stolons
and nutsedge nutlets.Non-selective, systemic herbicides or fumigants control
growing weeds and propagules. Choose materials that control all vegetation on the site yet have a short soil residual, allowing you to plant soon after treatment.Glyphosate is a non-selective systemic herbicide that the plant absorbs through its leaves then translocates to all other parts. To be sure that weeds have fully absorbed and translocated the herbicide to roots and propagules, it is best to wait a week after application before tilling the area. Soil microorganisms quickly deactivate glyphosate
once it comes in contact with the soil so you can plant soon after treatment.Fumigants are volatile materials that you apply to the soil in gaseous or liquid form. They kill all living organisms,
including seeds and other propagules in the upper layer of soil.• Test the soil. The best way to determine lime and fertilizer
requirements is with a soil test. By testing the soil, you can avoid spending unnecessary time, labor and money on materials that the soil doesn’t need. You also avoid applying excessive amounts of lime and nutrients, which could be detrimental to the future turf.• Rough grade and install drainage and irrigation systems.
Rough grading involves removing the topsoil and contouring the subgrade. By smoothing out surface irregularities,
such as steep slopes and depressions, you will greatly ease future maintenance. Steep slopes interfere
with mowing and make applying fertilizer and pesticides difficult. Irrigation also is difficult on slopes. Water often runs off before it can infiltrate the surface. If steep slopes face south, turf can suffer from heat and drought stress.When determining the contour, consider surface drainage. If the area will be heavily trafficked, such as an athletic field or golf course, contour the site so surface water can run off compacted areas. With athletic fields, add a l-foot crown in the center. Golf-course fairways, tees and greens should slope toward roughs. Home sites should slope away from the house to keep water out of basements.After contouring the subgrade, replace the topsoil, spreading it evenly over the site. Staking the area with markers showing the desired final elevation eases this operation. Topsoil settles after you spread it over the site. You can expect fine-textured soils to settle 5 to 10 percent.
Coarse-textured soils won’t settle as much. When marking the stakes, take this settling into account and mark them above the final settling level.
When filling areas with large amounts of topsoil, add the soil in 12-inch-deep layers, rolling between each one to speed settling. If the subsoil is considerably different than the topsoil, mix 2 inches of fill with 2 inches of subsoil to create a transition zone.Using soil amendments, modify topsoil that has a poor texture. Otherwise, the poor texture allows either compaction
or poor nutrient and water retention.Sandy soils don’t hold water or nutrients well. You can improve sandy soils by amending with organic materials or with calcined clay. These materials aid moisture retention
and increase cation-exchange capacity, minimizing nutrient loss. Organic amendments such as peat and compost work well.Because soil microbes break down organic matter, it is important to consider the stability of the material when choosing an organic amendment. Stable materials that resist decomposition will retain their soil-amending properties longer than materials that quickly decompose. The carbon:nitrogen ratio (C:N) is an indicator of the material’s stability. The higher the C:N ratio, the more stable the material. However, you must ensure the soil has adequate amounts of nitrogen when amending with material having a high C:N ratio. Microbes use nitrogen as they break down carbon components in the organic matter. The higher the C:N ratio, the more nitrogen it takes to break down the material. If soil nitrogen is low, the turf could become deficient.Peat is superior to other organic compounds because it is relatively stable and has a favorable C:N ratio. Reed-SEEDBED PREPARATION EQUIPMENTAA variety of seedbed-preparation equipment is available to help you get the job done on both large and small sites. Most are of three types: • Tow-behinds• Hitch-mounted units• Fast-mounting systems for frame-mounted attachments.Tow-behinds are attached to a draw bar that is bolted to a tractor frame. Hitch-mounted units use a tractor’s hydraulic 3-point-hitch system to lift them, so the operator controls the units’ functions and height. Fast-mounting systems usually take no more than 5 minutes to put in place.The following equipment types fall into these categories:# Rock pickers. You can rake top-side stones before planting, but it’s best to remove even small stones from the upper 4 inches of the root zone. These stones interfere with cultivation and damage machines. A stone-picking machine may handle the problem most effectively.Rock pickers are either ground- or PTO-driven and do a good job where rocks have been brought up to the surface. They operate best at 3 to 5 mph, and some models can pick rocks ranging from small stones to 200 pounders. Some can pick a ton of rock in 1 minute, so labor savings can be substantial.# Tractor rakes. Tractor rakes are especially efficient on stony or sandy soils. They remove trash and are particularly good for minimizing surface irregularities and contouring the subgrade.By angling these rakes, you can lay down windrows of rocks or trash for later pickup with trucks or front-end loaders. You also can add wheel and scarifier attachments for heavier soil.Soils in the West and Midwest often are too heavy for a tractor rake alone, so you may need to use a box scraper or scarifier/scraper on the area first. Many manufacturers make tractor rakes.# Rear scraper blades. Many of these blades, mounted on the rear of a tractor, include operator-activated tilt and angle controls. With the tractor in reverse, you can use the blade as a dozer. Rear blades use their own weight and the blade’s angle to dig.# Scarifiers. Two types of scarifiers handle different jobs. A scarifier/scraper uses teeth to rip up hard-packed soil while bringing stones to the surface. You can later drag the stones using the scraper blade. The scraper blade also roughly levels areas and spreads topsoil. On many units, you can easily switch the scarifier to the scraper by using a lever that rotates the unit.A scarifier/clod breaker works on level ground that hasn’t been finish-graded. The leading edge has fixed teeth that break up compacted
soil. A spiked roller bar follows and breaks clods turned up by the scarifier teeth. These units are best for light work and as preparation
for final hand raking.# Box scrapers. These attachments do an excellent job of breaking stones loose and leveling out an area’s high spots. Usually a welded brace keeps the box in a rigid position so the unit doesn’t rotate.Some box scrapers have a blade along the rear. The blade covers wheel tracks, while the box holds sand and soil being distributed over the area. Side shields on the blade trap scraped soil until the end of the pass, which controls soil placement. Optional scarifier teeth ahead of the blade can break up crusty soil.# Drags. A drag can be anything from a railroad tie to a large pipe to a heavy mat. Used for final smoothing, they’re usually hauled behind a tractor. Manufactured drags may have scarifier teeth, leveling bars or drag chains to smooth a surface. Drags are effective only on the soil’s surface.# Harrows. Some harrows look like chain-link fencing and are dragged behind a tractor. One side of a harrow has spikes that dig lightly into the soil. The other side is smooth and distributes soil side to side as it breaks up clods. It can remove light trash and cover seed, but it’s best use is for soil preparation.# Front-end loaders. Seedbed-preparation attachments for front-end loaders have a dual advantage. They can work the soil bed and lift loads, so debris can be put into a truck.Their hydraulic down-pressure can dig or make shallow passes to remove topsoil before grading. Front-wheel drive on many models is an additional advantage.
sedge peat is the most stable peat and is the preferred organic material for turf establishment. Add peat to the soil at the rate of 10 to 20 percent of the total volume of the mixture.You also can use coarse inorganic amendments for improving the structure of fine-textured, easily compacted
soils. Sand is the most widely used inorganic amendment. Another material that is good for this purpose
is calcined clay. Not only does it improve soil texture,
it also increases cation-exchange capacity and water retention. Calcined clay costs more to use than sand. Isolite is another inorganic amendment that shows promise. Research indicates that it improves aeration in heavy soils and aids water retention.Characteristics of a good coarse amendment include particle size, particle-size uniformity and durability of the material. The objective of using a coarse amendment is to create large pores in the soil. Sands that are too fine or that are composed of a wide range of particle sizes may actually impede water movement. Coarse amendments
that are not durable break up under traffic and lose their beneficial characteristics. For this reason, avoid materials such as vermiculite, perlite and diatomite.Because large pores are important in soil-water movement,
you must add enough coarse amendment that individual particles bridge, or touch, each other. The amendment may need to make up as much as 80 to 90 percent of the volume of the soil mixture. Have the soil and amendment physically tested by a university or commercial
soil-testing lab to determine the quality of the amendment and the native soil and to determine the amount of amendment to add.• Apply lime and fertilizer. Referring to soil-test results, incorporate any necessary materials 4 to 6 inches deep. In the absence of a soil test, you can apply fertilizer using standard recommendations. However, remember that you may be applying materials that aren’t needed, wasting
money and possibly creating detrimental conditions for the turf.Phosphorous is important to seedling rooting. Potassium
increases turfgrass resistance to stresses. Lime will correct an acid soil. Basic fertilizers, such as 10-10-10 and 0-20-20, supply phosphorous and potassium without adding excessive nitrogen. Because these materials are not mobile and don’t readily move in the soil, it is best to incorporate them into the soil before establishing the turf. Disk or rotary till them 4 to 6 inches deep following rough grading.• Finish grading. Finish grading will provide a smooth, firm seedbed free of obstructions. When the area has settled and the soil is moist—not too wet or too dry—it is ready for finish grading.Remove stones and other debris that may impede seedling emergence or interfere with future
turf maintenance.
If you have sufficient staff or the area is small, use hand rakes. Lightweight,
broad aluminum
or wooden rakes with closely spaced tines are best for removing small stones and smoothing the soil.To achieve a smooth firm surface, it is best to rake then roll, alternating procedures until footprinting on the soil surface is minimal. A water-ballast roller one-half to three-fourths full is easy to push and is heavy enough to firm the soil.For larger areas, use a cultipacker to firm and smooth the soil.• Apply starter fertilizers. Starter fertilizers supply young, shallow-rooted seedlings with an initial source of nitrogen. A soluble nitrogen source is best because it is readily available to the seedlings. If you didn’t incorporate
fertilizer in the soil during site preparation, you should use a complete fertilizer at this time.Apply starter fertilizer just before seeding or as you seed. Lightly rake the fertilizer into the upper 0.5 inch of the soil surface. Use 1 to l.5 pounds of nitrogen per 1,000 square feet. If the turf doesn’t sufficiently grow or green up, you can supplement the initial application with 0.5 pound of nitrogen per 1,000 square feet when the seedlings reach 1.5 to 2 inches in height. BUY HIGH-QUALITY SEEDHigh-quality turf starts with high-quality seed. High-quality seed is one of the most important prerequisites
for the establishment of a persistent, weed-free, high-quality turf. Poor-quality seed may be contaminated
with weed seed and undesirable turf species or varieties. It may have low purity and germination percentages.
Using poor-quality seed can lead to persistent maintenance problems in the future and can waste all the time, effort and money you spend on soil preparation,
fertilization, liming and seeding.Because turfgrass species and varieties are adapted to different environmental conditions, have varying levels of disease susceptibility and perform differently under varying levels of cultural intensity, it always is best to refer to local recommendations from county or state extension specialists.# Identifying seed. Botanically speaking, the turfgrass seed is a caryopsis. It is composed of an embryo, endoCaryopsis
PaleaLemmaTesta (seed coat).

sperm and the testa, or seed coat, which is fused to the ovary wall. The embryo is a rudimentary plant, and the endosperm provides energy reserves, allowing the embryo
to grow until it can manufacture its own food by photosynthesis.The turfgrass seed is not strictly a true seed. It is actually
a floret. The floret includes the caryopsis enclosed by two floral bracts called the palea and the lemma (see Figure 1, page 23). At the base of the palea is a stem-like structure
called the rachilla.The seed of most major turfgrass species is easily identifiable
through distinguishing marks on the seed. For example, seed size, shape, color, pubescence, awns, the number of nerves or veins running lengthwise on the lemma, and the shape of the rachilla can help you identify
the species making up a turfgrass blend.Seeds of species within the genera Agrostis (bentgrasses),
Poa (bluegrasses) and Festuca (fescues) are similar. So while you can identify the genus, you can’t easily tell the species in a mix. You won’t know if you have Kentucky bluegrass or rough bluegrass, hard fescue or red fescue. It’s also extremely difficult to distinguish among the varieties of a particular species.It is important to note that every rule has an exception. Seed harvesting, cleaning and packaging procedures can damage the distinguishing features of a seed. Thus, it’s best to look at several specimens before making a positive
identification.# Labeling seed. Regulatory agencies on the federal and state levels monitor the seed industry and enforce standards
for seed quality. The Federal Seed Act of 1939 regulates the sale, transportation and distribution of seed imported into the United States and seed that is transported
across state lines. Individual states also have seed laws. Although seed laws vary from state to state, they all require that seed packages have a label attached and that their contents meet basic minimum-quality requirements.
Although all seed must bear a label, the label alone doesn’t guarantee the varietal purity of the seed in the package. Seed regulatory agencies inspect seed during production and after harvest, mixing and packaging. Seed that meets the specifications of the state agency receive an official certification tag—a guarantee of varietal
purity.Specifications differ from state to state, and seed that is certified in one state may not necessarily meet the certification specifications of another state. In addition, certification doesn’t guarantee the other components of seed quality on the label: purity or germination percentage.
The seed label must provide some basic information. With this information, you can tell what turfgrasses you are buying and the proportion of each species in the bag. Information on the bag should include:• Name and address of the labeler• Lot number• Whether the turfgrass is fine- or coarse-textured• The turf species and varieties listed in order, starting with the variety making up the largest portion of the mix• The percent by weight of pure seed for each species and variety—the purity percentage (pure seed is the named species minus the amount of weed seed, inert matter, chaff and other crop seed)• The germination percentage or percentage of viable seed• Percent of other crop seed by weight• Percent by weight of weed seed, including that of restricted
noxious weeds• Percent of inert matter by weight• Number of restricted noxious weed seeds per ounce or pound• Date on which the germination test was conducted.The germination percentage that is listed on a label for a particular turfgrass seed reflects the germination capacity
of the seed. Germination percentages are calculated from the number of seeds that germinate in a test sample. TEMPERATURES FOR SEED GERMINATIONThe optimum temperature for seed germination alternates between
two significantly different temperatures—a reflection of what occurs naturally in spring and fall. The first temperature
lasts about 16 hours and the second for about 8 hours. For cool-season turfgrasses, the optimum day temperature for seed germination is higher than that of shoot growth. As a result, the ideal strategy is to plant in late summer. At that time, soil temperatures are optimum for germination, but they soon afterward
fall to the range optimum for shoot growth. The optimum soil temperature for root growth of cool-season species is 50°F to 65°F. Thus, late summer or early fall planting also benefits root growth.For grasses that spread by tillers, you can use less than the recommended seeding rate, but it will take more time for the turf to achieve complete coverage.For bunch-type species, such as fescues and ryegrasses, it is particularly important to use the suggested seeding rate. These species don’t spread to fill in voids between plants.Using a higher seeding rate than suggested will not achieve more rapid turf formation. Excessive seeding rates lead to an increased number of individual plants per area, but the stand is composed of spindly plants that are slow to form a mature turf. The plants remain in a juvenile state, which impairs lateral shoot development and sod formation.

Seed companies conduct germination tests on a seed lot every 9 months, and that date must be listed on the label.
Although companies take measures to reduce the amount of contaminants in a seed lot, contamination can occur. Inert matter is the percent by weight of any material
in the seed lot that will not grow. It may include chaff, small stones, sand, pieces of seed, asphalt or other bulking agents. The cleaning process normally reduces the amount of inert matter. However, companies sometimes
intentionally add it to “bulk up” the seed lot, making
less-expensive seed.There are two basic weed-seed categories: noxious and non-noxious. Noxious weeds are ones that, when established,
are objectionable and difficult to control through normal practices. You can further divide noxious weeds into prohibited and restricted weeds. Prohibited noxious weeds are exceptionally difficult to control, and laws ban their inclusion in seed mixes. Restricted noxious weeds are permitted in turfgrass seed lots, but at specified low amounts. Weed problems differ across the country, and states have established their own lists of prohibited and restricted noxious weeds.The label must state both the kind of noxious weeds and the number of weed seeds per pound. The label must also include a percentage by weight of all weed seed—noxious and non-noxious—present in the seed lot.The label also must list any seed considered a crop seed that is in the seed lot in amounts greater than 5 percent of the mix. When crop seed makes up less than 5 percent of the mix, it will be listed in a general “other crop seed” category. All other crop seeds will be combined as a total percentage of the seed lot by weight.In some cases, crop seed can cause serious, persistent problems for the future turf stand. Annual grasses and most broadleaf weeds are easily controllable. But it’s hard to control perennial grasses without killing the turf. Bentgrass, tall fescue, rough bluegrass and orchardgrass are crop seeds that are not compatible with Kentucky bluegrass. Even when present in amounts of less than 5 percent, such grasses will seriously detract from the quality of a Kentucky bluegrass turf.# Seed calculations. See “Appendix: Turf and Landscape Calculations” for seed calculations concerning seeding rate and pure-live seed, and determining the best buy for seed.SEED APPLICATIONSeeding is the least expensive and least labor-intensive means of propagating turfgrass. And it is the way most cool-season turfgrass species are established.The best time to seed cool-season turfgrasses is in fall. You can seed in spring, but summer annual weeds, such as crabgrass, compete with and often overrun the emerging
turfgrass seedlings. Also, summer weather can stress seedlings, causing stand losses.When sowing seed, strive to evenly distribute it over the seedbed at the proper rate and provide good seed-to-soil contact. Several types of seeders are available to help you meet these goals. You can seed by hand, but it requires considerable skill and is not practical for large sites.• Broadcast spreaders are appropriate for small or moderately sized areas. You can cover a wider area with these spreaders than you can with drop spreaders. However, wind can deflect seed coming out of broadcast spreaders, making it difficult to get a uniform distribution. Also they may not evenly distribute mixtures, as different-
sized seed can spin out at different rates. Be careful when seeding the boundaries of an area to ensure seed doesn’t go beyond the area, thus wasting seed.• Drop-type spreaders deliver seed through holes in the base of a hopper. The hopper has an agitator that helps force seed out of the holes. Seed placement is more accurate with drop spreaders than with broadcast spreaders. Wind is less of a problem. But it is easy to skip areas between application strips and to excessively overlap strips. The best use for drop spreaders is in small areas and along borders where you need accurate seed placement.• Disk-type seeders have vertical blades that cut slits in the soil. Seed drops into the grooves from a hopper behind the blades. Disk seeders place seed in direct contact with soil so more seed germinates with these types of seeders than with drop or broadcast seeders. You normally use lower seeding rates with disk seeders than you use with broadcast spreaders.• Cultipacker seeders are tractor-mounted units that not only uniformly distribute seed but also firm the seedbed after planting. The roller component is ridged to ensure proper seed placement. This equipment is appropriate for seeding large areas.• Hydraulic seeders are essentially large-capacity sprayers with a single-nozzle delivery system. Through them, you can apply a mix of seed, mulch, fertilizer and other materials to slopes and areas where other seeding methods
are impractical. Because this method doesn’t provide good seed-to-soil contact, it is critical that you mulch hydraulically seeded areas.# Uniform application. To ensure uniform application, make two passes over a site, the second one at right angles
to the first. In this way, you can cover any skips you make with the first pass. Calibrate the spreader to deliver
one-half the recommended seeding rate in each pass.# Seed-to-soil contact. If establishment is to occur, seed must be kept moist and have a place to anchor its
roots. Thus, good seed-to-soil contact is important for germination. Good seed-to-soil contact also prevents seed from drying too quickly and enables seedlings to root into soil more rapidly.With broadcast and drop spreaders, you should lightly rake the seed into the upper 0.25 inch of soil then roll to firm the soil. You don’t need to do this with disk seeders
or cultipacker seeders because they work seed into the soil as they go.# Mulching. Mulch helps provide a favorable environment
for germination and seedling development. It reduces
moisture loss while seed germinates and begins to grow and shades seedlings, minimizing daily temperature
increases. Mulch also helps stabilize the soil until seedlings have rooted.Many different mulches are available from which to choose. Straw mulch is most popular. It is easily obtainable
and inexpensive. Take care to ensure that the straw is free of weed-seed, or you could have future weed problems.Apply straw by hand or with a mechanical blower. Evenly distribute it to get 50-percent soil coverage—1 bale per 1,000 square feet or 1.5 to 2 tons per acre.Generally, you can leave straw mulch on the seedling stand because it will decompose in a relatively short time.Wind often blows straw mulch. Tie it down with twine, crisscrossed over the site and staked down. Asphalt
binder is often used to stabilize mulch on large areas. Apply it at the rate of 200 gallons per acre.Wood mulches such as wood cellulose fiber, wood shavings or excelsior are comparable to straw. Other wood mulches—sawdust, wood chips or bark mulch—can upset the soil C:N ratio and tie up much of the nitrogen
in the soil. These materials also do a poor job of modifying the seedling microclimate.Apply wood cellulose fiber by hand or as a slurry through a hydraulic seeder. You can buy excelsior in 4-foot-wide rolls or as a loose material. Apply it by hand or with a mechanical mulching machine.Burlap, cheesecloth, jute netting or tobacco shade cloth are good mulches for slopes or other critical areas, such as in drainage swales or around irrigation heads. When laid out and staked along a slope or drainage swale, they effectively stabilize seed and minimize moisture loss. These materials are biodegradable, so you can leave them to decompose on the site.Elastomeric polymer emulsions form a thin rubbery layer over the seedbed. When you apply these materials in a low-pressure stream of water using a 9:1 proportioner,
seed stabilization is good. With these materials, you judge the application rate by how well they cover the site. Be careful not to apply too much material as it could seal the surface and impede seedling germination.# Aftercare. Because seedling turf is much more sensitive
than mature turf, you must manage it differently. Seedlings don’t have the extensive root system of mature turf and can’t easily obtain water and nutrients. They are also more susceptible than mature turf to injury from disease, environmental stresses and herbicides.Proper irrigation is the most important management practice following seeding. If you don’t supply water once the seedlings begin germinating, the stand will be lost. Keep the upper 0.5 inch of soil moist during establishment.
Irrigate lightly and frequently until the turf matures. If you haven’t mulched the area, water several times during the day to prevent drying.Excessive watering can be as damaging as infrequent watering, especially during warm weather. Pythium blight is a fungal disease that is active when warm, moist or humid conditions prevail. It is particularly lethal to seedling turf and turf that is succulent from excess nitrogen.
The care you give young turf—frequent irrigation
and starter fertilizer—promotes perfect conditions for the development of Pythium blight.Other diseases can attack seedling turf, including damping off, root rot and seed rot. These can kill plants before or right after they emerge. Thiram or captan will reduce injury from damping-off organisms.Mow the seedling stand when its height is one-third greater than the recommended mowing height for the species. For example, you normally maintain tall fescue at 2 to 4 inches high. So when seedlings are between 2.7 and 5.3 inches, mow them to the recommended height.An exception to the rule is close-cut creeping bentgrass.
Begin mowing it at 0.5 inch, then gradually lower the cutting height as the turf matures.Take care not to uproot seedlings with the first couple of mowings. A well-sharpened mower blade can help here. To avoid making ruts in the seedbed, use a lightweight
mower. Or mow only when the seedbed is relatively
dry and firm.Apply nitrogen fertilizer 3 to 4 weeks after seedlings have emerged and have grown to 1 to 2 inches tall. Apply
soluble nitrogen at 0.5 pound actual nitrogen per 1,000 square feet. If you use slowly available nitrogen, use a rate of 1 pound per 1,000 square feet.Herbicides that you can use on mature turf may damage
seedlings. This is why it is so important to control as many weeds as possible before you establish the turf. Most herbicides require you to hold off on treatment until the turf has been mowed two to three times. Others
have a much longer waiting period. Siduron is the only pre-emergence crabgrass herbicide that you can apply before seeding. Before applying any herbicide to
new turf, read the label carefully. SOD INSTALLATIONA sodded area can be no better than the quality of the starting product. If sod is certified in your state, purchase
certified sod containing varieties well-adapted to your area. A scheduled visit to prospective suppliers’ fields will acquaint you with growers and the quality of sod they produce long before you take delivery. Make sure your supplier does the following things before harvesting the sod:• Maintains a uniform cut at appropriate heights for the individual turfgrass species.• Allows no more than 0.5- inch of uncompressed thatch. To reduce the potential for heat buildup in stacked sod (which can lead to transplant failure), make sure the grower removes excessive clippings.• Applies 0.25 to 0.75 pound of actual nitrogen per 1,000 square feet to improve color. (Avoid excessively fertilized sod, as indicated
by dark-green, lush leaves. Sod fertilized with excessive nitrogen in particular leads to stress-susceptible turf with poor rooting potential. Sod in this condition has a greater tendency to heat on the pallet and is more susceptible to transplant failure.)Although sod pieces come in various sizes, make sure the width does not vary by more than 0.5 inch to ensure installation ease and a uniform initial appearance. Make sure the sod is 1- to 0.75-inch thick, excluding thatch and leaf length. Thickly cut sod—1.5- to 2-inches thick—is sometimes used on specialty-use turf areas, such as athletic fields, to shorten the waiting time before the area is usable. However, for most turfgrass areas, thinly cut sod is easier to handle and roots more readily.
Test for sod strength by holding the sod by one end and observing whether it tears or loses its shape. Sod that falls apart easily may have been harvested too young or managed poorly. It is difficult to install and a high risk for successful establishment.# Soil preparation. Sod often fails to establish or perform
well because no one bothered to correct deficiencies
in the physical and chemical condition of the soil. Prepare soil as you would for a seedbed by first sending a soil sample for analysis by a reputable testing laboratory.
This will help determine the amounts of nutrients needed to correct deficiencies. Also, follow the laboratory’s
recommendations for correcting an acid or alkaline soil to pH 6.0 to 7.0.When renovating existing turf, remove the old grass below the thatch layer rather than tilling it in. Treat difficult-
to-control weeds with appropriate herbicides before
adding amendments. To improve the water-retention properties and soil structure of sandy or heavy clay soils, add about 30 cubic feet of peat moss per 1,000 square feet. Apply 1 to 2 pounds of actual nitrogen per 1,000 square feet. Apply fertilizer, lime or other amendments recommended by the soil test, incorporating all amendments
at least 6 inches into the soil. Rake the soil to a smooth, level finished grade and roll it to provide a firm planting bed.Where high-quality topsoil is difficult to obtain or economically prohibitive, incorporate sand and organic matter to improve existing soil conditions.# Schedule operations. Schedule operations carefully and complete all soil preparation before sod delivery. Install sod immediately after delivery—within 12 hours of harvest in warm weather and 36 hours during cool weather. Yellow leaves and signs of mold and mildew indicate that the sod remained on pallets or stacks too long, has reduced vigor and will establish poorly. Do not accept sod that arrives on site in this condition.# Supply adequate moisture. Sod is living turf with a limited root system, so make sure the sod remains moist until a new root system develops. Water the soil lightly before you install the sod, or schedule soil preparation so the soil is still moist when you install it. For high-quality turf, you cannot get away with irrigating only after installation.Irrigate again within 20 to 30 minutes of installing the first piece of sod. Thorough irrigation to a 6-inch depth immediately after installation should help maintain adequately
moist sod.Make sure all sod pieces are butted together tightly and do not overlap. Stagger the joints in each row the same way bricks are laid and use wooden stakes to hold sod in place on steep slopes. Roll sod to smooth the surface and to bring the bottom of the sod layer into intimate contact with the soil surface.Until the root system begins to develop, irrigate often enough to keep the sod pad moist; this usually means irrigating 0.25 inch per day for the first week after installation.
After a sufficient root system develops, reduce irrigation frequency and irrigate to a depth of 4 to 6 inches every 5 to 10 days.Bermudagrass sod may root sufficiently within 3 to 5 days and quickly allow a reduction in irrigation frequency.
However, Kentucky-bluegrass sod requires careful
irrigation for 2 to 3 weeks to become successfully established during summer-stress periods. Mow the newly sodded area when the turf exhibits a 30- to 50-percent increase in vertical-shoot growth. For example, if you maintained the sod at a 2-inch cutting height before harvest, you should mow for the first time when the grass reaches a height of 2.75 to 3 inches.Apply 0.5 to 1 pound of nitrogen per 1,000 square feet after 4 to 6 weeks if the grass begins to show signs of
chapter 4nitrogen deficiency. Use lower rates during summer on cool-season grasses and higher rates during more favorable
seasons. Use the higher nitrogen rate on warm-season
turf.A common practice on construction sites is to remove topsoil and haul it off-site. This practice brings heavy clay soils or soils with poor chemical characteristics to the surface. Before starting to establish sod, bring in a high-quality topsoil free of viable weed seeds, rhizomes or other propagative parts to replace what was removed.
Establish a subgrade with the existing soil material and adjust the upper 3 to 6 inches of the subgrade to a pH between 6.0 and 7.0. Grade and firm the subsoil to approximate
the final contour and slope. Make sure you have adequate surface drainage and, if necessary, install subsurface drain lines within the subgrade to ensure proper drainage. Spread enough high-quality topsoil to cover the subgrade at least 4 inches deep. Till it into the upper 2 to 3 inches of subsoil to prevent distinct layering between topsoil and subsoil.Correct any mineral nutrient deficiencies and adjust pH of the topsoil following the recommendations of a soil-testing laboratory. Establish the final grade. Smooth and firm the planting bed. Install your sod.RENOVATION# Correct pH, salinity or sodic soil problems. Once you make the decision to renovate a lawn, submit representative soil samples to a reputable soil testing laboratory 3 to 4 weeks before you need results. The soil test will indicate whether the soil is acidic or alkaline, an important consideration
because pH could have contributed to the original deterioration. Soil with a pH below 6.0 needs lime; alkaline soil with a pH above 7.4 needs an acidifying
material such as sulfur. The soil test will indicate the specific rate of lime or acidifying material to apply. Correct
soil pH at the time of soil cultivation, so the liming or acidifying material will move deeper into the soil.# Eradicate undesirable species/weeds. Whenever possible, renovate existing lawns by applying fertilizer and broadleaf<B