Sustainable Turf Care


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Sustainable Turf Care

  1. 1. SUSTAINABLE TURF CARE HORTICULTURE SYSTEMS GUIDE Abstract: This publication is written for lawn care professionals, golf course superintendents, or anyone with a lawn. Its emphasis is on soil management and cultural practices that enhance turf growth and reduce pests and diseases by reducing turf stress. It also looks at mixed species and wildflower lawns as low maintenance alternatives to pure grass lawns.By Barbara BellowsNCAT Agriculture SpecialistMay 2003 Table of Contents Introduction .................................. 2 Organic and Least-toxic TurfcareSPACE HERE FOR THE TABLE OF 2 LEAVE THIS Practices ........................ A ONTENTS, TO BE ENTERED LATER. C Healthy Soil Environment for Turf ........................................... 2 Species Diversity in the Lawn Environment ................................. 9 Cultural Practices that Reduce Stress on Turf .............................12 Biointensive Pest Control Methods for Turf .......................15 Summary .....................................20 Acknowledgements ...................20 Organizations .............................20 Resources .....................................21 Electronic Database ...................23 References ...................................23 Appendix: Tables 1-6 ........ 28-36 Illustration 1. A healthy lawn complements a healthy Executive Summary ...................37 garden. (Photo by Ron Francis, Natural Resources Conservation Service)ATTRA is the national sustainable agriculture information service operated by the National Centerfor Appropriate Technology, through a grant from the Rural Business-Cooperative Service, U.S.Department of Agriculture. These organizations do not recommend or endorse products,companies, or individuals. NCAT has offices in Fayetteville, Arkansas (P.O. Box 3657, Fayetteville,AR 72702), Butte, Montana, and Davis, California.
  2. 2. Related ATTRA Publications A Healthy Soil Environment for TurfFarm-Scale Composting Resource ListAlternative Soil Testing Laboratory Resource List Good quality soil with an active population ofAlternative Soil Amendments earthworms, fungi, bacteria, and beneficial nema-Sources of Organic Fertilizers and Amendments todes is critical for creating and maintainingFlame Weeding for Vegetable Crops healthy lawns. According to Dr. Eric Nelson (2),Notes on Compost Teas turfgrass specialist at Cornell University, “TheBiointensive Integrated Pest Control challenge of the turfgrass manager is to become an expert not only in the management of what everyone can see above the ground, but in theIntroduction management of beneficial soil microorganisms to maximize turfgrass health.”One 1996 survey found that more pesticides areused on turfgrass than on any other ornamental(1). High-maintenance turfgrass sites such as golf “The heart of organic lawn care is the naturalcourses use large amounts of fuel, fertilizer, pes- build up of your soil. Healthy soils nurture aticides, and water (2). However, homeowners, healthy turf, which grows much better andlandscapers, and golf course managers are be- has an increased resistance to stress causedcoming increasingly interested in organic and by heat, cold, drought, insect pests, diseases,least-toxic turf care. Reasons for this increased and weeds. A successful organic fertilizerinterest include (3): program provides for the long-term needs of • Elimination of pesticides from recre- your lawn by adjusting deficient nutrients ational areas such as lawns, parks, golf with organic fertilizers and soil conditioners.“ courses, and athletic fields to eliminate Shannon Pope, proprietor of Healthy exposure of people and pets Soils, an organic lawn care service • Decreased susceptibility of turf to pests, diseases, and drought “The challenge of the turfgrass manager is to • Reduced runoff and leaching of excess become an expert not only in the management nutrients and pesticides into surface and of what everyone can see above the ground, ground waters but in the management of beneficial soil mi- • Enhanced biodiversity in urban regions, croorganisms to maximize turfgrass health.” which contributes to the conservation of Dr. Eric Nelson, Cornell University species (birds, insects, herbs, others)Organic and Least-toxic TurfcarePractices Fungi, bacteria, beneficial nematodes, and earth- worms in the soil are important for the decom-Organic or least-toxic turf management reduces position of thatch, enhancing soil aerationstress on the turf. Turf experiences stress from through the formation of soil aggregates, andheat, drought, wetness, compaction, nutrient de- reducing populations of soil-borne plant patho-ficiencies or imbalances, and disease and pest in- gens. To support a healthy and diverse popula-festations. To minimizing stress on turf, you need tion of soil organisms, soils need to have on-go-to pay attention to the following principles: ing additions of organic matter, a near neutral • Establish and maintain a healthy soil en- pH, and a balanced supply of nutrients. In addi- vironment tion, soil organisms thrive best in soils that are • Include a diversity of species in the lawn well aerated and moist but not wet. environment • Use cultural practices that reduce stress Soil management practices that promote the on turf growth growth of beneficial soil organisms include: • Understand and work with your local soil • Adding compost and climate conditions • Monitoring soil pH and managing for • Use biological pest control methods consistent soil fertilityPAGE 2 //SUSTAINABLE TURF CARE
  3. 3. • Preventing soil compaction nisms that buffer and regulate the amount of • Reducing or eliminating the use of syn- nitrogen available to plants. thetic chemicals Unlike soluble, synthetic fertilizers that imme-Compost additions. Continued applications of diately release available nutrients into the soil,synthetic fertilizers and pesticides create a toxic the organic residues used to form compost mustenvironment for earthworms, fungi, bacteria, and decompose before their nutrients are availablebeneficial nematodes through radical changes in to plants. Good quality compost contains bothpH and the build up of toxic salts and other readily available and stored nutrients. Once com-compounds (heavy metals) sometimes found in post is added to the soil, weak acids secreted byfertilizers. In contrast, mature compost enhances plant roots release the available nutrients frompopulations of soil organisms by providing them compost, and over time soil organisms breakwith an excellent source of nutrients. down and mineralize additional nutrients. See Appendix, Table 1, for characteristics of goodSoil quality. When soil organisms use and de- quality composts.compose compost, they form slimes, gels, andfilaments that bind soil particles together into soft Compost maturity. As will be discussed in moreclumps called aggregates. Soil aggregates im- detail below, compost can effectively suppressprove conditions for turf growth by increasing some turf pathogens. However, the compostsoil pore space, which then allows for less re- must be mature—fully composted and cured—stricted root growth and easier flow of water, for it to provide these disease suppressive ben-nutrients, and air through the soil and to plant efits. In cured compost, heat-loving microorgan-roots. The low density of compost helps increase isms have decomposed the organic stock mate-soil softness or friability, while its high surface rials, and then more moderate temperature mi-area and chemical activity increase the water and croorganisms have stabilized various organicnutrient holding capacity of soil. Several turf acids into humus. Compost piles that are wellspecialists recommend applying high rates of aerated, contain a balanced mix of stock materi-compost to improve degraded soil (4, 5). The als, and are managed at optimum temperatureNOFA Standards for Organic Lawn Care (6) rec- and moisture content will decompose and cureommends applying one inch or three cubic yards more rapidly than less intensively managed com-of compost per 1,000 square feet for marginally- post piles. Mature compost will have generatedgood soils. For very sandy or low-organic mat- enough heat to kill most pathogens and weedter soils, they recommend a two-inch layer or six seeds and will have undergone sufficient miner-cubic yards of compost per 1,000 square feet. alization of organic materials to supply readily available nutrients (7, 8, 9).Compost as a fertilizer. Mature compost pro-vides turf plants with a balanced source of nu- You can make a preliminary assessment of com-trients that are released slowly into the soil. In post maturity simply by filling a plastic bag withtheir excellent book, Ecological Golf Course Man- moist compost, sealing it, and letting it sit in theagement, Paul D. Sachs and Richard T. Luff (4) sun for a few days. If the compost has an earthystate: smell when you open the bag, it is mature; if it …plants have a hard time understanding and smells of sulfur or ammonia, it is still immature adapting to the feast to famine scenario asso- (5). In addition, special soil analysis laborato- ciated with many chemical-feeding programs. ries can assess the types of microorganism domi- During periods when nitrogen is inadequate nating the compost pile and the level of biologi- plants respond by elongating roots. When a cal activity. The ATTRA publication Alternative tidal wave of nitrogen becomes available from Soil Testing Laboratory Resource List provides con- an application of soluble nitrogen, an extra- tact information and descriptions of the analysis diffusive root system absorbs more than the capabilities for many alternative soil testing labo- plant needs, some serious side-effects that in- ratories. clude disease susceptibility, insect attraction, burning, and other problems can occur. In a If you are purchasing compost, make sure that it healthy ecosystem, however, there are mecha- is from a reputable source and that it is mature, //SUSTAINABLE TURF CARE PAGE 3
  4. 4. nutritionally well balanced, and does not con- distribution. But adding sand to compost cantain heavy metals, pathogens, or other toxic sub- cause compaction problems if the topdressed soilstances (7, 9, 10). If you want to make your own is high in clay. To best mix compost with thecompost, the ATTRA publication Farm-Scale soil in existing turf, core aerate the turf, broad-Composting Resource List provides a compendium cast the compost, then run a drag chain over theof books and Web sites that can guide you. ground to sweep the compost into the aeration holes.Compost application. Compost can be tilled intothe soil during turf renovation, used as a The best time to apply compost is in the springtopdressing, or sprayed on as compost tea. Solid or fall. Compost applied in the spring providescompost can be applied as an unmixed material nutrients during the main growing season whileor mixed with sand for easier handling. The compost applied in the fall helps prolong themethod of application depends on whether you growing season, strengthens root growth for thewant to improve soil quality, enhance soil fertil- dormant season, and promotes early springity, or control pests and diseases. growth (12). As will be discussed in more detail later, compost mixed with cool-season grass seed in the fall facilitates effective overseeding. Managing for soil fertility. Turfgrass requires nitrogen (N), phosphorous (P), potassium (K), and other nutrients. As for fields or gardens, turf should receive fertilizer applications based on its nutrient needs. To accurately calculate the amount of compost needed to meet the nutrient needs of a lawn or turf, sample the soil at least every other year. Your local Cooperative Exten- sion Service can tell you how to collect and sub- mit soil samples for analysis. You may also want to refer to the ATTRA publication Alternative Soil Tilling compost into soil during lawn renovation. Testing Laboratory Resource List for laboratories that provide biological as well as chemical analy- ses. While soil sampling takes time and sampleWhen fertilizing turf, base the compost applica- analyses may be costly, good fertility manage-tions on the nutrient needs of the turf, which are ment can save fertilizer costs and help protectdescribed in greater detail below. To accurately water quality. The NOFA Standards for Organiccalculate the amount of compost needed to meet Land Care lists “adding nitrogen, phosphorus,the nutrient needs of a lawn or turf, sample the or potassium without a soil test” as a prohibitedsoil and test the nutrient content of the compost. practice (6).Since compost is a biological material, its nutri-ents are released slowly—depending on the qual- Nitrogen needs. Proper nitrogen fertilization isity and maturity of the compost and the climate especially important for healthy turf. Too littlewhere the compost is applied, only about one- nitrogen will yield turf that lacks vigor and goodthird to one-half of its nutrients are available color. Too much nitrogen reduces turf’s toler-during the first year after application. ance to drought and increases thatch (the layer of dead stems and roots that builds up beneathFor maintenance of existing turf, apply compost grass) and susceptibility to disease. Timing ofas a topdressing. Compost may be applied as an nitrogen applications is also critical. Cool-sea-unmixed material. However, in the turf indus- son grasses should be fertilized in the spring ortry, compost is typically mixed with sand 50/ 50, fall when grass roots and shoots are activelywhile for golf courses, topdressing mixes typi- growing. They should not receive fertilizer incally contain 70% to 90% sand and 10% to 30% the late spring or summer when they are dor-compost (4, 11). The advantages of mixing com- mant. Conversely, warm-season grasses shouldpost with sand are easier application and better be fertilized in the late spring or summer whenPAGE 4 //SUSTAINABLE TURF CARE
  5. 5. Guide for Determining Compost Application Rates (developed from information provided in references 4 and 12)Step 1. Test the compost nutrient content. A nutrient test should be conducted on each compost pile you willbe using. Especially if you are using commercial compost, test it for nutrient content as well as for thepresence of heavy metals or pesticides. If the compost is to be used for disease control, an analysis of micro-bial populations should also be conducted (see Table 1).Step 2. Determine the amount of nutrients needed. Most soil testing laboratories provide recommendationson the amount of nutrients to be applied, based on the type of soil and plant variety you will be using. Whencalculating the amount of nutrients coming from compost, remember that only about one-third to one-halfwill be available during the current growing season.For uniform turf growth throughout the growing season, apply the majority of your compost in the springand fall, with some topdressing during the summer. For example, you may want to apply 50% of the nutri-ents needed in the spring and 30% in the fall, with four topdress applications, each providing 5% of therequired nutrients.Step 3. Determine the weight of compost needed (nitrogen based)To calculate the amount of compost needed, divide the amount of nitrogen to be applied by the percentage ofnitrogen in the compost, for example:Nitrogen to be applied = 6 pounds /1,000 ft2Nitrogen content of compost = 2.0% on a dry weight basisMoisture content of the compost = 40% Thus:Compost to be applied = 6 pounds N/(0.02 x 0.4) = 750 pounds of compost / 1,000 ft2To translate pounds/1,000 ft2 into pounds/acre, multiply by 43.5. Thus:750 x 43.5 = 32,625 pounds or 16.3 tons of compost would be needed to cover an acre.Step 4. Calculate the volume of compost neededBulk compost is usually sold by the cubic yard rather than by weight. To calculate the volume of compostneeded, you need first to determine the weight of the compost for a given volume, such as a cubic foot.For example, if your compost weighs 25 pounds per cubic foot:then, its weight per cubic yard is 25 pounds/ ft3 x 27 ft3/ yd3 = 675 pounds/yd3Continuing with the example given above:750 pounds of compost /675 pounds per yd3 = 1.1 yd3 /1,000 ft3 of compost needed. Or32,625 pounds of compost /675 pounds per yd3 = 48.4 yd3 / acre needed.Step 5. Depth of compost layer to applyIt is easier to apply compost by thickness rather than by weight per area. To convert cubic yards of compostneeded into thickness of the compost layer to be applied:Divide yd3/1,000 ft2 by the conversion factor 3.086 OrDivide yd3 /acre by the conversion factor 134.44.Continuing with our examples:1.1 yd3 /1,000 ft3 needed / 3.086 = 0.35 inch or 3/8 inch of compost to be applied.or 48.4 yd3 / acre /134.44 = 0.35 inch or 3/8 inch of compost to be applied.Note that normal agronomic compost application rates range from 5 to 10 tons/acre. The recommendedcompost application rates for turf are higher than the agronomic rates, because of the higher economic valueof turf and, depending on its use, the greater potential for compaction by people walking or playing sports onyards or athletic fields. For restoring degraded land, the recommend rates for compost additions can be ashigh as 250 cubic yards or 84 tons per acre, especially when the natural topsoil is missing (5). //SUSTAINABLE TURF CARE PAGE 5
  6. 6. they are actively growing. These grass speciesshould not be fertilized in the fall or winter whenthey are dormant (13, 14).Turf species, soil conditions, length of the grow-ing season, and cultural practices all affect theamount of nitrogen fertilizer required. In gen-eral, cool season grasses such as Kentucky blue-grass, fine fescue, tall fescue, and perennialryegrass require 2 ½ to 3 pounds of N per 1,000square feet (109–130 lbs./acre) per year, whilewarm season grasses such as bahiagrass andbermudagrass require 5 to 10 pounds of N per1,000 square feet (217–435 lbs./acre) (13, 15). Turfneeds more nitrogen in southern states, wherethe growing season is longer, compared to north-ern latitudes where the growing season isshorter.Compost as a source of nutrients. Compost pro-vides a complete source of turf nutrients, includ-ing micronutrients. Since these nutrients must Illustration 2. Soil testing helps you provide your lawn with the correcteither be dissolved into solution by organic ac- amount of nutrients without risking contamination of the environmentids or mineralized by microbial activity prior to (Photo by Lynn Betts, Natural Resources Conservation Service)becoming available before they are available toplants, several weeks may pass before turf grassresponds to initial applications of compost. An- Soil pH refers to the acidity (soil pH lower thannual or semi-annual applications of compost will 7) or alkalinity (pH greater than 7) of a soil. Mosteventually provide a continual release of nutri- turf grasses thrive best at a near neutral pH ofents to turf. This nutrient release will slow or 6.5 to 7.5. Soil that is either too acid or too alka-cease during the winter, when cold temperatures line hinders the availability of nutrients. It alsoslow the growth of soil organisms. As a result, limits the ability of soil organisms to release nu-turf that is dependent on compost for nutrients trients from compost, to form soil aggregates, andmay green up slowly in the spring. If you want to break down thatch. At a low pH, phospho-green turf early in the spring, you will probably rus, calcium, and magnesium become deficient,need to supplement compost with other natural and nitrogen fixation by clover and soil algae isor synthetic nitrogen sources. impaired. At a high pH, the micronutrients iron, manganese, and boron become unavailable forNatural nutrients sources. While compost is an plant uptake.excellent natural nutrient source, its balance ofnutrients may not be the same as those required To raise the soil pH (make the soil less acid), ap-for healthy turf growth. Consequently, you may ply lime. Lime is available in two mineral forms:occasionally need to apply more targeted nutri- as a pure calcium limestome or as a combinationent supplements. Table 2 contains a list of nutri- of calcium and magnesium, referred to as dolo-ent supplements and their designation as organi- mite. It is also available in different grinds.cally approved, permitted, or prohibited. For Finely ground limestone is more chemically re-additional information on soil amendments and active and will change soil pH relatively rapidly,organic fertilizers and where to obtain these while more coarsely ground limestone may re-products, see the ATTRA publications Alterna- quire a year or more to affect soil pH. To lowertive Soil Amendments and Sources of Organic Fer- soil pH, add sulfur, typically available in the formtilizers and Amendments, respectively. of the mineral gypsum.PAGE 6 //SUSTAINABLE TURF CARE
  7. 7. The nitrogen in topdressed fertilizers is subject This is particularly true for compost made fromto loss through volatilization. Between 13% and animal manure and less of a problem when com-60% of the nitrogen in urea topdressed on turf is post is made from lawn clippings and other land-lost to volatilization. Similarly, much of the avail- scape materials. However, organic matter addi-able nitrogen in topdressed compost can be lost tions stimulate microbial activity, which in-to the atmosphere before it becomes available for creases the capacity of soil to hold nutrientsplant growth (16). Incorporating compost or fer- against leaching and runoff (18).tilizer into the soil can decrease the chances forvolatilization. As will be discussed in more de- Soluble nitrogen applied through an irrigationtail below, core aerating the soil prior to apply- system has less potential for leaching than if it ising compost allows it to fall into the aeration broadcast or topdressed on the sod, since onlyholes and become partially incorporated into the small amounts are added to the soil with eachsoil. application. Organic soluble nitrogen sources include fish emulsion, fish powder, bat guano,Caution when applying nitrogen to turf. Use care seabird guano, worm castings, manure teas, andnot to overapply nitrogen to turf. Large doses of compost teas. Synthetic slow-release nitrogensoluble nitrogen can injure or kill both plants and fertilizers, such as sulfur coated urea or resin- andsoil organisms. If you are using synthetic sources polymer-coated materials such as Osmocote™of nitrogen, nitrate forms of nitrogen tend to be and Nutricote™, are less likely to contaminateless injurious to turf than ammonic forms. Im- groundwater than are soluble fertilizers.mature compost or other materials with a highnitrogen content should not be used in the prepa- For large turf areas such as golf courses, parks,ration of new or renovated turf, since these ma- or athletic fields, ponds or constructed wetlandsterials can cause seedling death (16). High ni- can collect and treat nutrients and sedimentstrogen availability also increases the succulence from storm water runoff. These areas also canof turf grasses and their susceptibility to attack provide flood control, wildlife habitat, and aby pests and diseases, including chinch bugs, sod source of irrigation water (14).webworms, parasitic nematodes, and brownpatch. Preventing and correcting soil compaction. Turf grows poorly in compacted soil because its root growth is hindered, water infiltration is slowed, and water and nutrient movement through the The average homeowner uses ten times more soil is restricted. Compacted soils also put stress chemical fertilizers per acre than farmers use on turf by creating greater temperature extremes. on farmland (17). You can decrease soil compaction by aerating the soil and providing the soil with regular additions of compost.Turf fertilization and water quality. Applyingtoo much fertilizer or providing turf with nutri- People walking, exercising, or playing on theent applications that are out of balance with the grass can compact turf soils. Even mowing thenutrient needs of the turf can cause water pollu- lawn can compact the soil, especially if the soil istion problems. The average homeowner uses ten moist or wet when it is mowed. Applying hightimes more chemical fertilizers per acre than rates of nitrogen fertilizer (especially ammonicfarmers use on farmland (17). Too much nitro- nitrogen) and continually removing grass clip-gen fertilization, especially when applied to bare pings without adding organic matter back to theground or when plants are not actively growing, soil also contribute to soil compaction.can result in nitrogen leaching into the ground-water. Overfertilization with phosphorus fertil- Turf soil may be thin and compacted because ofizers can result in phosphorus runoff, which con- the natural characteristics of the soil in the areatributes to algae growth in lakes and streams. or because of poor landscaping following hous-Depending on the source materials used in com- ing construction. Often when homes are built,post production, continual applications of com- the topsoil is removed or heavy equipment com-post can cause phosphorus to build up in the soil. pacts the soil. If nothing is done to lessen the //SUSTAINABLE TURF CARE PAGE 7
  8. 8. soil compaction or if only a fraction of the top-soil removed is put back, turf will grow poorly.It will also be subject to water and nutrient stress,because the soil is too thin or consists largely ofnutrient-poor and easily compacted clay subsoil.Thatch. Thatch is turf root growth that forms onthe surface of compacted soils. Lawn clippingsdo not form thatch. In fact, if managed prop-erly, they can help break down thatch. Thickthatch contributes to soil compaction and hin-ders water infiltration, soil aeration, and thegrowth of soil organisms. Over fertilization andover watering causes a thick thatch to build up. smaller yards or in yards where thatch is builtup in isolated areas, raking can loosen it. You A professional aerator.can leave this loosened thatch on the lawn todecompose or add it to your compost pile. Larger heavier mixture that will fall into the holes moreyards may require a mechanical dethatcher. readily. The compost stimulates the activities ofHowever, large dethatchers can be very destruc- earthworms and soil microbes that break downtive to turf and the soil structure. Many turf pro- excess thatch, form soil aggregates, and createfessionals prefer using management practices tunnels through the soil. As biological activitythat encourage natural thatch decomposition by in the soil increases, mechanical aeration may noearthworms. Regular applications of compost, longer be required. Instead, biological aeration,combined with soil aeration, provide earthworms stimulated by regular surface applications ofand other soil organisms with the air, moisture, compost, may be sufficient (7, 19, 20).and nutrients they need to grow and break downthatch (4, 19). While adding topsoil may appear to be the solu- tion to thin soils, this treatment must be under-Aeration. Turf soils can be aerated by regularly taken with care. Many commercial topsoils con-applying compost to stimulate microbial activ- tain a plethora of weed seeds and may containity or by combining mechanical aeration with heavy metals or toxic chemicals. The type of soilcompost additions. The appropriate type of me- added may not be compatible with the soil be-chanical aeration for you depends on the size of ing treated, with the resulting soil mixture beingthe lawn or field you are treating. You can aer- compacted. If a lawn or field has very thin soilate a very small lawn with a garden fork, by in- and soil additions are necessary, make sure toserting the fork 6 inches deep every 4 to 6 inches get the soil from a reputable source. If you areand working it back and forth gently. On larger unsure of the soil quality, or you are going toyards, you can use a mechanical, walk-behind work with a soil supplier on a regular basis, youaerator. These machines pull cores 2 to 3 inches may want to analyze the soil for contaminantsdeep. For best results, make three or more passes such as heavy metals. When adding topsoil, mixacross the yard, then break down the cores left it with compost before applying it to the turf.on the soil surface with a rake or drag chain. For Then till this compost-soil mixture into the ex-fields and larger turf areas, tractor-mounted isting soil so that there is no clear dividing line“shatter-core” aerators can treat deep compac- between the existing and the new soil (19).tion or drainage problems by penetrating 6 inchesor more into the soil (19). Reducing or eliminating the use of synthetic chemicals. Earthworms, other soil invertebrates,Following mechanical aeration, topdress com- and soil microorganisms are essential for main-post onto the field or lawn. The topdressed com- taining soil structure, recycling organic debrispost will fall into the core holes, resulting in a such as thatch, and mineralizing nutrients in turfpartial incorporation of the compost into the soil. soils (7, 19). Most pesticides are toxic to earth-Mixing 40% compost with 60% sand produces a worms. Similarly, the soluble fertilizers ammo-PAGE 8 //SUSTAINABLE TURF CARE
  9. 9. nium nitrate and methyl urea significantly reduce ance in mid-summer. A mixture of appropriateearthworm populations (21). Both pesticides and turf species also protects the whole yard againstfertilizers kill soil organisms through direct tox- pests and diseases. Your local Cooperative Ex-icity. They also retard their ability to regrow by tension Service can provide you with informa-increasing soil acidity and compaction. In addi- tion on turf varieties and cultivars that are ap-tion, high soil nutrient concentrations associated propriate to your area.with fertilizer additions suppress the growth ofmychorrhizal fungi, a type of soil organism that Good quality seed is fundamental to establish-assists grass in taking up nutrients and water ing good turf. Read and compare seed labelsfrom the soil. carefully before purchasing turf grass. Inexpen- sive mixtures often contain seeds of grasses thatIn contrast to soluble fertilizers, compost contains either have weedy characteristics or are annualscarbon and nutrients that promote the growth and need to be reseeded yearly. Common fillerof soil organisms. Making the transition from a grass varieties include annual ryegrass, orchardchemically maintained turf to an organic or least- grass, timothy, annual bluegrass, bentgrass, andtoxic turf can reduce thatch build up and pro- rough bluegrass (22, 23). To avoid weed controlduce a turf that is resistant to pests and diseases. problems, use seed from a reputable dealer and check the label for the following information (23):Species Diversity in the Lawn • Grass variety listed by trade name — not by generic name, e.g. Aries KentuckyEnvironment bluegrass rather than just Kentucky blue grassTurf species. Turf composed of a single species • Germination rate of seed —should be atis highly susceptible to becoming weedy and least 75% for Kentucky bluegrass and 85%demands more nutrients and water than turf for otherscomposed of a diversity of species (12). To mini- • Weed content less than 0.5%mize maintenance problems, use species that are • Inert matter less than 5%appropriate for your location and for the specific • No noxious weeds stated on the labelconditions within the yard. Also, choose variet-ies that are resistant to common pests in the area A good source for comparative information onand that do not demand a lot of nitrogen. the performance of different turf varieties under a range of environmental conditions is the Na- To minimize maintenance problems, use only tional Turfgrass Evaluation Program (NTEP) species that are appropriate for your location Web page, <>. Trials and for the specific conditions within the yard. conducted nationwide by the NTEP are designed to help breeders and growers select cultivars that are well-adapted to their particular areas or spe-Table 3 (see Appendix) lists growth characteris- cific turf uses.tics of common turf grasses. Within these spe-cies, different varieties have been developed to Mixed species lawns. For greater diversity, youprovide specific advantages, such as shade tol- may want to consider mixing Dutch White Clo-erance, resistance to a particular pest or disease, ver (Trifolium repens) or subterranean clovers (Tri-or the ability to stand up to wear. Often, a mix- folium subterraneum) into the turf mixture (3, 6).ture of grasses performs better than a single spe-cies. For example, Kentucky bluegrass is oftenmixed with tall fescue or fine fescue to providebetter wear and disease resistance. In more Cool-season grasses do most of their growingnorthern areas, a mixture of fescue and ryegrass during the spring and fall, while warm-sea-allows for rapid soil coverage, less weed inva- son grasses have their strongest growth dur-sion, and better adaptation to both sun and shade ing the summer. Root growth for cool-seasonconditions (19). In mid-latitude locations, a mix- grasses peaks during the two months prior toture of cool season and warm season grasses al- maximum shoot growth in the spring andlows for cold tolerance at the beginning and end during the two months following the peak ofof the season along with heat and drought toler- shoot growth in the fall. //SUSTAINABLE TURF CARE PAGE 9
  10. 10. Illustration courtesy of Bob Mugaas, University of Minnesota Department of Horticulture.By evenly blending clover with grass seed, you In more arid or degraded landscapes, black mediccan obtain a uniform distribution of clover in the is a good complement to turfgrass or wildflow-lawn. Adding clover to the turf cover can: ers in a natural lawn. It can also serve as a tem- • Increase the drought-tolerance of the porary restoration crop to aid in turf establish- lawn ment. Like clover, medic fixes nitrogen, helps • Provide two pounds of nitrogen per 1000 aerate the soil with its deep root system, grows square feet annually close to the ground, and is non-invasive (24). • Decrease disease infestations by increas- ing the population of pest predators In addition to legumes, a combination of grasses • Decrease weed infestations native to your locality can provide a highly re- sistant, low-maintenance yard or turf. For ex- ample, a combination of little bluestem (Schizachyrium scoparium), common or Pennsyl- vania sedge (Carex pensylvanica), and tufted hairgrass (Deschampsia flexuosa) is well adapted to the Northeastern coastal areas (25), while blue grama (Bouteloua gracilis), buffalograss (Buchloe dactyloides), purple three-awn (Aristida purpurea), and sideoats grama (Bouteloua curtipendula) are native grasses of the arid South- west (26). You can get information on grass na- tive to your area from your Cooperative Exten- sion office. Some nurseries have created “no mow” lawn mixes composed of slow growing turf grasses, such as hard fescue and creeping red fescues. These grasses require little maintenance since they have deep roots and are resistant to drought.Illustration 3. Dutch white clover is an excellent addition The fescue mix is suitable for the cooler, medium-to a mixed species lawn. ( rainfall areas of the upper Midwest and north-clover1.htm) eastern United States, and southern Canada (27,PAGE 10 //SUSTAINABLE TURF CARE
  11. 11. 28). Sedges and rushes serve as a low-mainte- of sand and compost mix (33). Then, in thenance ground cover suitable for moist climates. spring, remove any remaining plant growth byGenetically-modified “no-mow” grass varieties burning it or scalping the soil with a lawnmowerare also being developed. Researchers creating before planting seeds. If you wait until spring tothese varieties have identified a gene in grasses start preparing ground for wildflower planting,that controls plant height by restricting the ac- you can till the soil, allow one to two weeks fortivity of a growth hormone (29). weeds to grow, kill the weeds with a herbicide or by flame weeding, then plant the wildflowerWildflowers. Including wildflowers as part of a seeds. For more information on flame weeding,yard provides options for adding color and vari- see the ATTRA publication Flame Weeding forety to your landscape. The diversity of species Vegetable wildflower lawns or meadows increases pestand disease resistance while attracting beneficial Mixing wildflower seed with an annual coverinsects and birds. Substitution of different plant crop helps control weeds while enriching the soil.varieties permits easy adaptation to local sun, You can use either agronomic cover crops suchshade, and moisture conditions. And since wild- as buckwheat, annual flax, wild rye or oats, orflower meadows are not usually mowed, they you can use native cover crops. Evening prim-are perfect for slopes, ditches, and other hard- rose, black-eyed Susan, and nodding wildrye areto-manage areas (30, 31). appropriate for the upper Midwest, while purple three-awn and Mexican hat are suitable for theChoosing seed. To ensure that a wildflower South or Southwest (28).planting will thrive, select wildflower mixturesthat are either native to or well adapted to the Since many wildflower seeds are small, you havelocal climate and soil conditions. Note that many better control over their distribution if your mixnon-native, naturalized species, including Queen them with compost, potting soil, or sand beforeAnne’s Lace, chickory, Dame’s Rocket, Ox Eye broadcasting. Attempt to plant approximatelyDaisy (Shasta Daisy), Bachelor’s Button (Corn fifteen to thirty seeds per square foot. This willflower), and Butter and Eggs, are used heavily ensure that there are enough plants to crowd outin most commercial wildflower seed mixes be- weeds without the wildflowers being so closecause they grow rapidly on freshly worked soil. together that they are not able to bloom (31, 33).Since these plants exhibit aggressive, weedy be-havior, they can readily out-compete other spe-cies or contribute to weed infestations in sur-rounding areas (31).Establishing a wildflower lawn. A wildflowerarea is often difficult to produce from seed be-cause many home owners or lawn managers areunable to distinguish weeds from desirableplants when the plants are still small. While fallplanting allows for earlier blooming of flowersin the spring, spring planting allows for better Illustration 4. Wildflowers add diversity to lawns. (Photoweed control (32). by Lynn Betts, Natural Resources Conservation Service)As with any turf management practice, success- Wildflower seed mixtures. Most wildflower mix-ful establishment of a wildflower lawn requires tures contain a combination of perennial, bien-appropriate land preparation. Surprisingly, nial, and annual plants. While the early bloom-wildflower gardeners usually discourage tilling ing annual plants produce a large quantity ofsince it can destroy seeds of prairie species lay- seed, much of this seed will probably not fall oning dormant in the soil, hurt tree roots, and cause bare ground. Reseeding annuals into the wild-erosion. A common method of land preparation flower planting each spring will help maintain ais to first smother the existing turf over winter balance between annuals and perennials, as wellunder layers of newspaper held down by a layer as decrease the potential for weed competition. //SUSTAINABLE TURF CARE PAGE 11
  12. 12. Grasses, especially native warm-season prairiegrasses, are a natural complement to wildflow-ers. The grass species little bluestem (Andropogonscoparius), sideoats grama (Bouteloua curtipendula),and indiangrass (Sorghastrum nutans) are excel-lent companions for wildflowers since they growreadily on almost any normal, well-drained soil,and can tolerate very dry conditions. In contrast,common lawn grasses —such as Kentucky blue-grass, tall fescue, and smooth bromegrass — too aggressively to serve as good compan-ions to wildflowers (31). Recently laid wildflower turf. ture of grasses appropriate to your locality. Good soil preparation, including soil tillage or aeration and compost incorporation, will enhance estab- lishment and help maintain the healthy and pro- ductive growth of either grass or wildflower sod. Mulches. Mulches serve as attractive and low- maintenance complements to turf. They are par- ticularly useful in shady or wet areas that do not support healthy grass growth. They can also be used on walkways or other areas that receive heavy traffic. Organic mulches are preferable, since they decompose and add organic matter toIllustration 5. Prairie grasses can add diversity and beauty the soil. However, inorganic mulches, such asto a natural lawn (Photo courtesy of Prairie Nursery,Westfield, WI.) stones, can be reused and do not need to be re- plenished as often as organic mulches. When using mulches, do not pile them too high. ThickTo rapidly establish a wildflower area, you can mulches hinder air and water movement throughpurchase wildflower mats or wildflower sod. the soil, stimulate trees to sprout surface roots,Wildflower mats are usually made of a wood fi- and favor burrowing and plant damage by her-ber, are biodegradable, and serve as a mulch to bivores (6).help keep down weeds while the seeds impreg-nated into the mat are germinating (34). Wild- Cultural Practices that Reduce Stressflower sod costs considerably more than seeds on Turfor mats, but this method is probably the mostlabor saving and dependable method for estab- By creating healthy soil and selecting appropri-lishing a wildflower area. As with the selection ate species for your climate, you have taken theof seeds, carefully review the list of plant species first steps towards establishing a healthy turf.included before purchasing sod or mats. Wild- The next steps involve mowing and wateringflower sods or mats that have the greatest po- practices that stimulate rather than stress planttential for retaining blooms will contain plants growth. Overseeding allows you to quickly re-that are either native to or compatible with local juvenate turf that has come under stress or toenvironmental conditions and have a high per- extend the length of time that turf grass is ac-centage of perennial species. tively growing and remaining green.Choosing and installing sod. Most sod contains Mowing correctly can kill weeds, save water, re-high-maintenance grasses and is grown using duce diseases, stimulate root growth, and pro-synthetic inputs. If you use sod, try to choose vide grasscuttings for fertilizer (35). Mowing in-one grown that uses compost and contains a mix- correctly can cause stress on turf, introduce dis-PAGE 12 //SUSTAINABLE TURF CARE
  13. 13. eases, promote weed growth, and encourage that are returned to the soil, rather than beingthatch build-up. collected and bagged, replenish organic matter and can annually add between 2 to 5 pounds ofReducing stress. Increasing the height of cut nitrogen per 1000 ft2 (12, 19). If you use a non-during mowing is key to reducing stress on mulching mower and leave clippings on the soil,grasses and increasing the vigor of both leaf and mow lawns early in the day to allow the clip-root growth. Research trials and the experience pings left on the ground to dry out so that theyof turf professionals have demonstrated that in- do not serve as a source for disease transfer (4).creasing the mowing height to 2 to 2 ½ inchescan reduce weed invasions, encourage deeper Manual reel mowers provide less soil compac-root growth, and improve drought resistance tion while eliminating polluting emissions asso-(19). For native grass lawns, heights up to 3 ciated with gas mowers. For smaller yards,inches are recommended (20, 36). Time the in- manual mowers do not require great effort, es-tervals between mowings so only one-third of pecially when the mower is sharp and the grassthe grass is removed each time you mow. This is cut at an appropriate time and height. Whenmoderate trimming helps stimulate root growth choosing a mower, be careful to get a model thatwithout significantly reducing the leaf area avail- is able to cut to a 2 ½ to 3 inch height, since manyable for photosynthesis. reel mowers are not adjustable.Increasing the mowing height is particularly Mower maintenance. Maintaining sharp mowerimportant when turf is under stress by heat, blades enhances mowing efficiency, reducesdrought, or shade. Do not leave your mower set stress on grass, and facilitates decomposition ofat the same height all year—or even while you grass clippings. Sharp mower blades also reduceare mowing different sections of your lawn on mower vibration, lengthen mower life, and re-the same day. Instead, increase the mower duce fuel consumption by gasoline mowers byheight to reduce stress on turf growing in the as much as 22 percent (14). Conversely, a dullshade and when you mow during the summer blade favors the spread of diseases since it cutsheat. Since turf species grow more slowly when grass with a rough tear that provides more sur-they are under stress, the time between mowings face area for disease to enter than does a cleanshould allow turf in hot or shady conditions to cut. Many turf professionals recommend sharp-regrow sufficiently before it is mowed again. ening mower blades at least once a month, orThis may mean mowing shady sections of your after eight hours of mowing (12).lawn at intervals different from those used insunny areas. By increasing your mower height, Water management. Healthy lawns that are wellyou can both reduce stress on turf species as well aerated and have a moderate to high level of or-as the incidence of some common turf weeds. In ganic matter need less water than do more com-contrast, probably the most stressful mowing pacted lawns. Soils that are not compacted al-practice for turf grass is allowing grass to reach low for good water infiltration and movementa height of 7 inches or more, then mowing it to a to plant roots, while organic matter acts as aheight of 2 inches or less just before the summer sponge, absorbing water and holding it for usedrought. This abrupt change in height shocks during dry periods.and seriously weakens a lawn (19). Proper watering. Watering less frequently and more deeply encourages root growth deep into By increasing mower height, you can both re- the soil rather than on the surface, where it forms duce stress on turf species as well as the inci- thatch. Deeper root growth allows plants to with- dence of some common turf weeds. stand dry conditions better, and the formation of less thatch enhances soil aeration. Deep rootsMower type. Mulching mowers and grasscycling have better access to soil nutrients and water,mowers chop grass clipping finely and blow especially in the dry season. They also promotethem down into the turf. This provides a lawn turf growth over weed growth, since many turfwith a clean appearance while encouraging rapid grasses develop a deep root system, while manydecomposition of the clippings. Grass clippings weeds have shallow roots (36). //SUSTAINABLE TURF CARE PAGE 13
  14. 14. systems, encourages water logging, increases the Mowing guidelines to reduce turf stress (36): potential for a variety of soil-borne diseases, and • Mow grass higher when temperatures stimulates the growth of weeds such as butter- are high to encourage more root cup, speedwell, and annual bluegrass (19). Wa- growth and reduce soil temperatures. tering during the morning places less stress on • Manage grass located in shady or grass and decreases the potential spread of fun- moist areas differently from grass lo gal diseases (37). cated in sunny areas: grass in shady areas should be mowed to a higher Heat management. Reducing the water supply height and less frequently than grass to the lawn just before to the onset of the sum- in sunny areas. mer heat prepares a lawn to become dormant • Regularly sharpen mower blades, (37). However, deeply watering the lawn once since tearing grass with dull blades during each rainless month allows turf grasses creates stress and provides an ideal to retain enough growth to remain competitive entry point for pathogens. with deep-rooted weeds such as dandelions (19). • Clean mowers regularly to remove If your area receives a light rain during an other- potential sources of inoculum that wise dry month, the best time to water is imme- could be spread to other parts of the diately following the rain to ensure that the full lawn or field. root-zone has become wetted (31). If you want to maintain green lawns throughoutMost grasses are adapted to seasonally dry con- the hottest days of summer, water the grassditions and compete best if the soil in the root briefly (for about 10 minutes) every hot after-zone is allowed to become partially dry between noon, to minimize heat stress, then providewaterings. For best turf growth, wait until the heavy waterings as needed. You can test soilsoil has dried to a depth of 2 to 4 inches then moisture by feeling the top 2 to 4 inches of theirrigate to replenish the water to the depth of the soil to see whether it has become dry, or you canroot zone (19). When rewetting a dry soil, slowly use a moisture meter. You can also rely on evapo-wet the surface, wait an hour or so for the water transpiration information for the area that is pro-to penetrate, then thoroughly irrigate the lawn. vided by local weather stations or agriculturalIf you do not pre-wet the soil, you will loose colleges. Applications of seaweed extract canwater and soil nutrients to runoff, since dry soil further reduce heat stress in turf. By stimulatingis water repellent and does not allow good wa- antioxidant production, the natural hormones inter infiltration (19, 36). seaweed may help grasses sustain a balance be- tween photosynthesis and respiration (4, 36). Leaving grass clippings on the soil and For best turf growth, wait until the soil has topdressing with compost also mulches and cools dried to a depth of 2 to 4 inches then irrigate the soil while stimulating microbial activity. to replenish water to the depth of the root zone. Overseeding. Overseeding is a practice that al- lows you to rejuvenate a lawn and fill in bareWatering also needs to be timed according to the spots where weeds might otherwise grow (19).soil texture, the rate of water infiltration into the Overseeding also allows you to slowly replacesoil, and the flow rate of your irrigation or sprin- inappropriate or disease-prone varieties withkling system. If you apply water faster than the more appropriate or more disease-resistant va-soil can absorb it, the excess will run off rather rieties. In some areas, overseeding extends thethan soak into the soil (22). Besides being waste- length of time a lawn remains green into the fall.ful, this runoff can transport diseases across the For lawn rejuvenation, overseeding may be donelawn and may cause water pollution if it runs either in the spring (April or May) or in the fallinto storm sewers or creeks. (September or October). Prior to broadcasting seed into the existing turf, make a pass over theOverwatering. Watering grass too frequently or area to be overseeded with an aerator or heavytoo lightly causes lawns to develop shallow root rake. Or you can plant seed with a slice-seeder.PAGE 14 //SUSTAINABLE TURF CARE
  15. 15. These techniques provide the conditions for good overfertilization, choosing locally appropriateseed-to-soil contact. Seed can be broadcast or and disease resistant turf species, and mowingplanted alone, followed by a topdressing layer and irrigating correctly are practices that reduceof compost. If turf seed is broadcast planted, it turf stress while also reducing the potential forcan be mixed with compost, and the two can be pest and disease infestations. Cultural controlbroadcast together onto the prepared turf (19, 23). measures, such as using a diversity of species andFollowing seed planting, press the seed into the removing disease-infested leaf litter from thesoil with a roller or, for small renovation patches, lawn, also help prevent pests and diseases fromby walking on the overseeded area. becoming established or spreading. If preventa- tive measures are not entirely effective,In the mid-latitude, humid areas of the country, topdressing with compost and employing bio-warm season grasses thrive in the summer and logical pest and disease control agents are goodcool season grasses thrive in the fall and into part ways to protect your turf.of the winter. Under these conditions, you canmaintain a green lawn throughout much of the Once you are aware of a pest or disease prob-year by establishing a turf dominated by peren- lem, your first step is to identify the cause of thenial warm season grasses, then overseeding in damage. The Resources section of this publica-the fall with an annual cool season grass. The tion lists several books that you can use to iden-overseeded grass will keep the turf green into tify weeds, insects, and turf diseases. Personnelthe fall and continue growing in the early spring. at your local Cooperative Extension office shouldThen it will die out when the warm season also be able to help you identify and treat turfgrasses reemerge in late spring. pest problems.Biointensive Pest Control Methods Turf diseases. Prevention is the key to diseasefor Turf management in turf. Planting resistant variet- ies, keeping mower blades sharp, avoiding over-Biointensive pest control seeks primarily to pre- fertilization and over-irrigation, and biologicallyvent pest and disease infestations by reducing enriching the soil with mature compost are prac-turf stress and encouraging the growth of pest tices that will produce a vigorous, disease-resis-predators. Building soil quality, avoiding tant turf. “My program begins with a detailed lawn evaluation. I look first at the turf type. Then, I look for problem areas. Most of the time the weeds that are in the lawn will tell me what are the problems and what needs to be done. For example, are they summer, winter, or spring weeds? Are they annuals or perennials? Can they be controlled using pre-emergence measures or are they better controlled after emergence? Can they be spot controlled, or do control measures need to be used across the turf area?” “What time of year are you evaluating the lawn? If it is early spring and there are bare spots, a summer annual weed will probably invade. Look for problems with shade from trees, any disease or pest problems, too much or too little water, and thatch build-up. Key in on the condition of the turf. Is it thick and well-established? Or, is it thin and patchy? Take a shovel and look at your soil and the root systems of the grass. This is where most problems begin. If there are several inches of healthy soil and a strong root system, then a maintenance program is all that is needed. However, if the soil is thin and the roots are short or bunchy, the lawn needs an application of compost or other organic material to build-up the soil.” “Be realistic and don’t make promises to your clients that you cannot keep. It will take time to adjust deficiencies. Take advantage of the highest growing period of your turf types. This is when most noticeable gains can be achieved and when the turf needs the greatest amount of nutrients and care.” Shannon Pope, proprietor of Healthy Soils, and organic lawn care service //SUSTAINABLE TURF CARE PAGE 15
  16. 16. Cultural control practices for turf grass diseasecontrol include (20): • Altering the environment within the turf crown by raking, coring, or spiking • Applying natural supplements such as lime, ash, compost, liquid seaweed, or fish emulsion to alter disease-favoring conditions in the turf crown • Overseeding with turf varieties that are resistant to diseases • Waiting for weather conditions to change and seeing whether this reduces or elimi- nates disease symptoms Brown patch disease can be controlled by the application of certain types of compost.A list of specific cultural control practices thatare effective against certain turfgrass diseases is suppressive composts contain thoroughly de-provided in Table 4 (see Appendix). composed organic materials that have been al- lowed to “cure.” During curing, bacteria andPest and disease control with compost. In addi- other microorganisms that help form humus andtion to providing a steadily available source of suppress diseases replace the heat-loving organ-nutrients, compost suppresses some turf patho- isms involved in the early stages of organic mat-gens. Research at Cornell University (2, 11) dem- ter decomposition. Compost that has been ster-onstrated that topdressing with compost sup- ilized or allowed to decompose until most of thepressed some soil-borne fungal diseases just as available nutrients have been used is biologicallywell as conventional fungicides. This effect inert and unable to suppress diseases (4, 16, 39).lasted about thirty days, but was lost by sixtydays after the application (12, 38). Diseases Compost applications control diseases by sup-shown to be suppressed by compost include: plying the soil with millions of microorganisms • dollar spot (Sclerotina homeocarpa) in that are antagonistic to turf pathogens. Compost creeping bentgrass and annual bluegrass also provides nutrients that stimulate the growth • brown patch (Rhozoctonia solani) in creep- and reproduction of antagonistic organisms al- ing bentgrass, annual bluegrass, tall fes- ready in the soil. However, the type of compost cue determines the type and numbers of soil organ- • pythium root rot (Pythium raminicola) in isms and the degree of disease suppression they creeping bentgrass and annual bluegrass provide. • typhula blight (Typhula spp.) in creeping bentgrass and annual bluegrass Compost can suppress diseases in two ways. It • red thread (Laetisaria fuciformis) in peren- may contain a high population of disease-sup- nial ryegrass pressive organisms, or it may contain substances • pythium blight (Pythium aphanidermatum) that stimulate the growth of disease suppressive in perennial ryegrass organisms already present in the soil. Prelimi- • necrotic ringspot (Leptosphaeria korrae) in nary results from studies conducted by Eric Kentucky bluegrass Nelson and his colleagues at Cornell University (8) indicate that compost derived from eitherCharacteristics of disease suppressive composts. The brewery sludge or municipal biosolids was ef-composition, age, and preparation methods of fective in controlling the soil-borne fungal dis-composts are keys to their providing disease sup- ease Pythium, because it contained high popula-pressive benefits. Compost must be mature and tions of disease suppressive organisms. How-fully cured to suppress diseases. Immature com- ever, compost derived from poultry litter, whilepost has a high concentration of ammonic nitro- as effective in controlling Pythium did so by pro-gen (NH4 ) and increases, rather than decreases, viding appropriate nourishment to disease sup-the incidence of Fusarium diseases (39). Disease pressive organisms in the soil.PAGE 16 //SUSTAINABLE TURF CARE
  17. 17. Different composts provide selective control ofsome diseases. For example, composted sewagesludge increased the incidence of Fusarium oncarnations and peas, but decreased the incidenceof Fusarium on cucumbers (40). Composted poul-try litter provided 75% control of brown patchbut only 15% control of typhula blight, whilecomposted brewery sludge provided only 25%control of brown patch but 70% control oftyphula blight (40). Studies by Elaine Inghamand her coworkers (42) indicate that compostmade from succulent materials such as grass clip-pings, green leaves, food waste, and manure is A compost tea brewing tank in California.probably best for turf production, since these Steve Divermaterials favor high bacterial populations. Incontrast, compost made from woody materials,straw, and dry leaves favors the growth of fungi Microbial fungicides. If preventative measuresand is best used for the production of tree crops. are ineffective in controlling diseases, you can use microbial fungicides that are labeled for turf.To obtain optimum disease control, broadcast The fungus Trichoderma harzianum helps controlmature compost monthly. Applications of pesti- several diseases, including brown patch (causedcides or highly concentrated soluble fertilizers by the pathogen Rhizoctonia solani), dollar spotwill disrupt or kill beneficial soil organisms and (caused by Sclerotinia homoecarpa), and pythiumminimize the effectiveness of the compost. A root rot and blight (caused by Pythiumtopdressing of solid compost can be applied graminicola) (45). Commercial products contain-alone or as a mixture of 70% compost and 30% ing Trichoderma include BINAB T™ from BINABsand, then incorporated into the soil with an aera- Bio-Innovation AB, a Swedish company, andtor or drag chains. Alternatively, compost tea, a Turfshield™ from BioWorks, Inc. Companion™,liquid solution prepared from high quality com- produced by Growth Products, is a concentra-post, can be applied as a spray. tion of four species of Bacillus bacteria. It is rec- ommended for both general maintenance andCompost tea. You can make anaerobic compost remedial treatments of turf diseases. Studiestea by soaking a burlap bag full of compost in a conducted at the Rutgers Center for Turfgrassbarrel of water for up to two weeks. Soaking for Science showed that applications of Compan-four to seven days at temperatures below 65° to ion™ caused a 30 to 50% reduction in summer70° F provides the highest level of disease sup- patch (45). A new anti-fungal strain of bacteriapression (8). Aerobic compost is prepared in the labeled as APM-1 is being developed for turf usesame manner, except that the ratio of water to by researchers at the New England Turfgrasscompost should be no more than 10 to 1, and the Foundation. It is not currently available com-compost should be soaked in the water for no mercially, but may be in the near future (4, 46).more than 48 hours. Another method for pro-ducing aerated compost is to add compost to a For additional information on biological or bo-brewer or vat that has air bubbling through it. tanical treatments of turf grass or horticulturalBoth anaerobic and aerobic compost extracts pro- plant diseases, see the Agrobiologicals Web pagetect against plant diseases (43). Research exam- (<>). Thisining the effect of compost tea on golf greens page has an excellent database of pests and dis-found that treated grass had longer roots, fewer eases. It also lists biological and botanical con-diseases, and higher density than untreated turf. trol products and contact information for theFor this study, compost tea was applied weekly companies selling bi-weekly at the rate of one gallon per 1000square feet (44). For more detailed information Turf insect pests. While pesticides kill insecton the production and use of compost teas, see pests listed on their labels, many pesticides arethe ATTRA publication Notes on Compost Teas. non-specific. That is, they kill beneficial insects //SUSTAINABLE TURF CARE PAGE 17
  18. 18. as well as pests. Pesticides also kill many soil • Using pest- and disease-resistant variet-organisms that decompose organic matter, form ies and seeds that contain endophytesaggregates, and suppress diseases. As a result, (see below).pesticides may decrease insect infestations in theshort term, but create other conditions that in- To effectively control turf pests, it is necessary tocrease turf stress. Thus, turf managed with pes- correctly identify the pest and understand its lifeticides often has more pest problems and requires cycle. The Resources section of this publicationmore intensive management than turf managed lists books that provide detailed descriptions ofwith biological products. turf insect pests, their major host species, and their growth cycles. Secondly, scout for pests above ground, in soil samples, or emerging from the ground when you apply soapy water to the soil. Monitoring provides information on the presence and changes in populations of insect pests. By combining monitoring and life cycle information, you can determine whether infes- tations have reached a point where some treat- ment is required (19, 47). Endophytes. Perennial ryegrass and many dif- ferent types of fescue are bred with endophytes— fungi that live symbiotically within the cells of the grass. Grasses that contain endophytes pro- Grubs feeding on turf. duce a bitter toxin that repels most insects and kills many of those that continue to feed. Be-Cultural control measures. As with the control sides protecting grasses from insect pests, endo-of turf diseases, preventative cultural control phytes also produce hormone-like substancesmeasures can greatly reduce insect damage. Cul- that stimulate the growth and vitality of the grass.tural control practices for turf insects include: Care must be used when planting endophyte- infected seed, since the endophyte will die if the seed is stored too long or at too high a tempera- • Reducing stress on turf by building up ture. However, once the endophyte-infected soil quality with regular additions of grass is planted, the endophyte grows and re- mature compost, protecting the soil from produces with the grass as long as the grass re- compaction, avoiding over fertilization mains viable (4). and over watering, and increasing the mowing height. Biological and botanical insecticides useful in turf • Decreasing thatch through a combination management include (4): of aeration and compost applications to stimulate the activity of thatch-eating • Beauveria bassiana, an entomopathogenic earthworms. (insect-eating) fungus • Increasing the diversity of plants within • Bacillus thurengiensis (Bt) a bacteria used the turf as well as in gardens, flower beds, in the control of turf eating caterpillers and other areas adjacent to the lawn. • Milky spore, formed by the bacteria Ba- Natural areas, in particular, serve as use- cillus popillae, controls Japanese beetle ful refuges for many beneficial insects. grubs Plants in the parsley (Umbelliferae) and • Entomopathogenic (insect-eating) nema- daisy (Compositae) family are especially todes control grubs useful for encouraging the growth of • Neem, a botanical insecticide derived parasitic wasps (20). from the leaves of a tree native to India • Syringing or applying about 1/10 of an • Repellents containing garlic juice and ex- inch of water mid-day during hot, dry tracts from hot peppers that persuade in- weather helps control chinch bugs and sects to go elsewhere to lay their eggs lawn grubs (20). • Insecticidal soapsPAGE 18 //SUSTAINABLE TURF CARE
  19. 19. Biological insecticides need to be handled and and decrease infestations from weeds, makeapplied with care in order to be effective. Since management changes to alter these weed enhanc-control is a result of the activities of living or- ing conditions.ganisms, the source of the product and how it isshipped affect the viability of the organisms (48). Mowing to control weeds. Raising the mowerIn addition, soil conditions at the time of appli- height reduces the incidence of some commoncation must be favorable to the growth of the turf weeds. Research conducted at the Univer-organisms. For example, entomopathogenic or sity of Maryland showed that mowing turf at 3insect-eating nematodes survive best in moist, inches, especially during the spring, provided asloamy soils that have soil temperatures between much control of crabgrass as did the use of her-65° and 85° F. Since they are able to withstand bicides (50). The higher cut reduced the stresshigh pressure, you can apply these biological on the turfgrass and they were able to choke outcontrol organisms using a sprayer or irrigation the (49). The ATTRA publicationBiointensive Integrated Pest Management provides Mowing at a lower cut during seed set can helpdetailed information on biological control prac- control annual bluegrass, crabgrass, goosegrass,tices. It also contains extensive lists of suppliers foxtail, barnyardgrass, fall panicum, andfor biopesticides and microbial pest control dallisgrass. This technique must be carefullyagents. timed to coincide with early seed set. Attach a clippings bag to the mower to collect and removeTable 6 (see Appendix) summarizes cultural and seed heads. Also be careful not to mow so lowbiological control measures for common turf in- that you stress the desired turf species (4).sect pests. When not mowing to collect and remove seedTurf weeds. Weeds are plants growing in the heads, leave the grass clippings on the soil to con-wrong place. The type of lawn you are inter- trol weed growth. Clippings from a variety ofested in having will define which plants are different turf species contain allelopathic com-weeds. For example, for someone developing a pounds that suppress the germination andnatural lawn, white clover is an integral compo- growth of certain weeds (4, 47). Many tur grassnent of the turf. For people wanting a pure grass roots also produce allelochemicals that suppresslawn, white clover is a weed. Using good turf the growth of weed seeds. Raising the mowingmanagement practices that favor the growth of height favors root growth and the production ofdesired species allows these plants to out-com- these allelochemicals.pete undesired species. Essential managementpractices for weed control include (22): Corn gluten meal is effective in the pre-emer- gence control of various weed species, includ- • Growing grass species appropriate for ing crab grass, foxtail, pigweed and dandelion. your region and your soil conditions This animal feed product controls weed growth • Eliminating soil compaction by inhibiting root formation (51). Studies dem- • Reducing wear on the lawn or turf onstrate that repeated applications increase the • Providing turf soil with appropriate and effectiveness of this natural herbicide. These balanced levels of fertilization studies show that corn gluten meal initially re- • Overseeding with cool-season grasses to duced weeds by 60 percent, by 80 percent the maintain grass growth in the fall and second year, and by 90 percent in the third year. spring The main drawback to using corn gluten meal is • Watering turf deeply and infrequently its high cost, which makes its use economically during dry periods feasible only in small areas. The average cost is • Ensuring proper drainage $1.50/lb., with recommended applications rates • Increasing mowing height of 40 to 65 pounds per 1,000 square feet (52). Since it contains 10% nitrogen, it should be managed Table 5 (see Appendix), which summarizes soil, as both a fertilizer and a herbicide. Universityweather, and management conditions that favor of Iowa turfgrass researcher, Nick Christians hasthe growth of weeds. To reduce stress on turf compiled a list of suppliers of corn gluten meal, //SUSTAINABLE TURF CARE PAGE 19
  20. 20. which is available at: turf growth and reduces the potential for dis-< eases. Similarly, watering infrequently—but to6-20-1997/cornglut.html>. the depth of root penetration—minimizes both turf stress and the environmental conditions thatVinegar has recently gained attention as an ef- favor root diseases. A diversity of species withinfective natural post-emergence herbicide. It a lawn reduces insect and weed by degrading the waxy cuticle layer on Natural lawns including clover, wildflowers, orweed leaves, resulting in desiccation. More fre- groundcovers that are drought or shade tolerantquent applications or applications with a stron- add variety to a landscape while reducing main-ger solution are needed to control weeds with tenance time and expenses.very thick cuticle layers. While vinegar typicallycontains approximately 5% acetic acid, distilla- Acknowledgementstion can increase this concentration to 15%, andfreeze evaporation can increase it to 30%. Re- This publication is a rewrite of the ATTRA Sus-search conducted by the USDA Agricultural Re- tainable Turf Care publication by Lane Greer, andsearch Service demonstrated that vinegar at 10, many of the organizations and resources listed15, or 20% acetic acid concentrations killed 80 to in this publication were taken from this earlier100% of giant foxtail, common lambsquarters, publication. ATTRA specialist Steve Diver iden-smooth pigweed, and velvetleaf (53). Some gar- tified compost and compost tea references, whiledeners have seen increased effectiveness by add- ATTRA specialist Rex Dufour provided pest anding lemon juice to the vinegar and applying it disease biocontrol references. They both pro-during the heat of the day (53). vided excellent review assistance. Shannon Pope, proprietor of Healthy Soils, an organicLike corn gluten meal, vinegar is an expensive lawn care service in northwest Arkansas, pro-treatment for large areas. Approximate costs for vided insightful, practical turf management in-broadcast application of vinegar are $66.00 per formation, which he permitted me to include inacre for 20% acetic acid and $99.00 per acre for this publication.30% acetic acid (54). OrganizationsWhile vinegar readily degrades in the soil andhas no long-term impact on soil organisms (soil Golf Course Superintendents Assoc. of AmericapH decreases at the time of application but re- 1421 Research Park Dr.turns to its original level in less than two days), Lawrence, KS 66049-3859it is caustic. When applying this material, you Telephone: 800-472-7878, 785-841-2240should wear a mask to avoid inhalation and http://www.gcsaa.orggloves to prevent skin contact (55). The Golf Course Superintendents Association of America (GCSAA) supports research on en-Summary vironmentally sensitive turfgrass care. Their magazine, Golf Course Management, includesA lawn that is healthy requires less irrigation and articles on least toxic pesticide use and prac-resists pests and diseases. Establishing and main- tices, integrated pest management (IPM), bio-taining a healthy lawn means reducing or elimi- logical control, wildlife and golf courses, waternating conditions that put stress on the turf. A saving practices, and compost use in golf coursesoft, microbially-rich soil allows for rapid water management, among other topics.infiltration, good water and nutrient holding ca-pacity, unimpeded root growth, efficient nutri- Turfgrass Resource Center / Turfgrass Produc-ent mineralization, and effective antagonistic ers Internationalcontrol of pests and diseases. Regular additions 1855-A Hicks Rd.of mature compost enhance soil quality while Rolling Meadows, IL 60008providing biological control of diseases and cer- Telephone: 800-405-8873, 847-705-9898.tain weeds. Raising mowing height to 2 ½ to 3 FAX: 847-705-8347inches, keeping mower blades sharp, and return- E-mail: info@TurfGrassSod.orging mower clipping to the soil stimulates healthy Web page: http://www.TurfgrassSod.orgPAGE 20 //SUSTAINABLE TURF CARE
  21. 21. A member’s Web page with information about Resources turfgrass varieties, turf soil management, and lawn watering practices. Also includes a data- Books base of turfgrass specialists. Least-toxic and Organic Lawn CareNational Turfgrass Evaluation Program Standards for Organic Land Care: Practices for De-Kevin Morris, Executive Director sign and Maintenance of Ecological Landscapes.National Turfgrass Evaluation Program Organic Land Care Committee. 2001. 66 p.10300 Baltimore Ave. Bldg. 003, Rm. 218 Northeast Organic Farming Association of Con-Beltsville Agricultural Research Center-West necticutBeltsville, MD 20705 PO Box 3Telephone: 301-504-5125 Northford, CT 06472-0386.E-mail: Web page: <>Web page: This manual describes how to grow an organic The National Turfgrass Evaluation Program lawn following an ecological stewardship phi- (NTEP) is one of the most widely-known losophy for designing and maintaining land- turfgrass research programs in the world. NTEP scapes. Written by landscape professionals, sci- currently evaluates seventeen turfgrass species entists, and citizen activists. It includes lists of in as many as forty U.S. states and six prov- preferred, allowed, and prohibited materials and inces in Canada. Their Web page provides an- practices for organic land care. Purchase of this nual evaluation results on turfgrass quality, manual includes the booklet A Citizen’s Guide color, density, resistance to diseases and insects, to Organic Land Care, which answers, in cus- tolerance to heat, cold, drought, and traffic. tomer-friendly terms, the questions: what is an organic lawn? and what are the advantages ofUnited States Golf Association Green Section an organic lawn?P.O. Box 708Far Hills, NJ 07931 Organic Lawn CareTelephone: 908-234-2300 Bruneau, A.H., Fred Yelverton, L.T. Lucas, andUSGA Publications: 1-800-336-4446 Rick L. Brandenburg. 1997. Publication AG-562.Web page: North Carolina Cooperative Extension Service.default.aspx 32 p. Golf course maintenance publications cover turf Department of Agricultural Communications management, IPM for golf courses, landscape North Carolina State University restoration, environmental issues for golf course Box 7603 management and construction, irrigation sys- Raleigh, NC 27695-7603 tems, waste water reuse, and bird conservation Practical information for homeowners. Main- on golf courses. tenance schedules, sources of organic fertiliz- ers, organic control strategies for insects andNOFA Accredited Organic Land Care Profes- diseases, and recommended cultivars and plant-sionals ing dates for North Carolina.c/o NOFA ConnecticutPO Box 386 Handbook of $uccessful Ecological Lawn CareNorthford, CT 06472-0386 Sachs, Paul D. 1996. 290 p.Web page: Edaphic Pressprofessionals.php PO Box 107 They wrote the Standards for Organic Land Newbury, VT 05051 Care. Their Web page also lists names of Telephone: 802-222-4277 lawncare professionals in the Northeast who are Well-researched handbook, written for profes- NOFA Accredited Organic Land Care Profes- sionals who install and maintain lawns. The sionals. //SUSTAINABLE TURF CARE PAGE 21