Sustainable Turf Care

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 Bellows
NCAT Agriculture Specialist
May 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 Center
for 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. Related ATTRA Publications
A Healthy Soil Environment for Turf
Farm-Scale Composting Resource List
Alternative Soil Testing Laboratory Resource List Good quality soil with an active population of
Alternative Soil Amendments earthworms, fungi, bacteria, and beneficial nema-
Sources of Organic Fertilizers and Amendments todes is critical for creating and maintaining
Flame Weeding for Vegetable Crops healthy lawns. According to Dr. Eric Nelson (2),
Notes on Compost Teas turfgrass specialist at Cornell University, “The
Biointensive 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 the
Introduction management of beneficial soil microorganisms
to maximize turfgrass health.”
One 1996 survey found that more pesticides are
used on turfgrass than on any other ornamental
(1). High-maintenance turfgrass sites such as golf “The heart of organic lawn care is the natural
courses use large amounts of fuel, fertilizer, pes- build up of your soil. Healthy soils nurture a
ticides, and water (2). However, homeowners, healthy turf, which grows much better and
landscapers, and golf course managers are be- has an increased resistance to stress caused
coming 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 fertilizer
interest 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 Turfcare
Practices 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 aeration
stress on the turf. Turf experiences stress from through the formation of soil aggregates, and
heat, 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 fertility
PAGE 2 //SUSTAINABLE TURF CARE

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 must
environment for earthworms, fungi, bacteria, and decompose before their nutrients are available
beneficial nematodes through radical changes in to plants. Good quality compost contains both
pH 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 by
fertilizers. In contrast, mature compost enhances plant roots release the available nutrients from
populations of soil organisms by providing them compost, and over time soil organisms break
with an excellent source of nutrients. down and mineralize additional nutrients. See
Appendix, Table 1, for characteristics of good
Soil quality. When soil organisms use and de- quality composts.
compose compost, they form slimes, gels, and
filaments that bind soil particles together into soft Compost maturity. As will be discussed in more
clumps called aggregates. Soil aggregates im- detail below, compost can effectively suppress
prove conditions for turf growth by increasing some turf pathogens. However, the compost
soil 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 organic
nutrient holding capacity of soil. Several turf acids into humus. Compost piles that are well
specialists 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 temperature
NOFA Standards for Organic Lawn Care (6) rec- and moisture content will decompose and cure
ommends 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 generated
good soils. For very sandy or low-organic mat- enough heat to kill most pathogens and weed
ter 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 with
their excellent book, Ecological Golf Course Man- moist compost, sealing it, and letting it sit in the
agement, Paul D. Sachs and Richard T. Luff (4) sun for a few days. If the compost has an earthy
state: 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. nutritionally well balanced, and does not con- distribution. But adding sand to compost can
tain heavy metals, pathogens, or other toxic sub- cause compaction problems if the topdressed soil
stances (7, 9, 10). If you want to make your own is high in clay. To best mix compost with the
compost, 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 the
of books and Web sites that can guide you. ground to sweep the compost into the aeration
holes.
Compost application. Compost can be tilled into
the soil during turf renovation, used as a The best time to apply compost is in the spring
topdressing, or sprayed on as compost tea. Solid or fall. Compost applied in the spring provides
compost can be applied as an unmixed material nutrients during the main growing season while
or mixed with sand for easier handling. The compost applied in the fall helps prolong the
method of application depends on whether you growing season, strengthens root growth for the
want to improve soil quality, enhance soil fertil- dormant season, and promotes early spring
ity, 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-
http://www.planetgreen.com/education.shtml?performance 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 sample
When 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 protect
described in greater detail below. To accurately water quality. The NOFA Standards for Organic
calculate 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 prohibited
soil 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 is
ity and maturity of the compost and the climate especially important for healthy turf. Too little
where the compost is applied, only about one- nitrogen will yield turf that lacks vigor and good
third 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 beneath
For maintenance of existing turf, apply compost grass) and susceptibility to disease. Timing of
as 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 or
try, compost is typically mixed with sand 50/ 50, fall when grass roots and shoots are actively
while for golf courses, topdressing mixes typi- growing. They should not receive fertilizer in
cally 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 should
post with sand are easier application and better be fertilized in the late spring or summer when
PAGE 4 //SUSTAINABLE TURF CARE

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 will
be using. Especially if you are using commercial compost, test it for nutrient content as well as for the
presence 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 recommendations
on the amount of nutrients to be applied, based on the type of soil and plant variety you will be using. When
calculating the amount of nutrients coming from compost, remember that only about one-third to one-half
will be available during the current growing season.
For uniform turf growth throughout the growing season, apply the majority of your compost in the spring
and 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 the
required 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 of
nitrogen in the compost, for example:
Nitrogen to be applied = 6 pounds /1,000 ft2
Nitrogen content of compost = 2.0% on a dry weight basis
Moisture content of the compost = 40%
Thus:
Compost to be applied = 6 pounds N/(0.02 x 0.4) = 750 pounds of compost / 1,000 ft2
To 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 needed
Bulk compost is usually sold by the cubic yard rather than by weight. To calculate the volume of compost
needed, 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/yd3
Continuing with the example given above:
750 pounds of compost /675 pounds per yd3 = 1.1 yd3 /1,000 ft3 of compost needed.
Or
32,625 pounds of compost /675 pounds per yd3 = 48.4 yd3 / acre needed.
Step 5. Depth of compost layer to apply
It is easier to apply compost by thickness rather than by weight per area. To convert cubic yards of compost
needed into thickness of the compost layer to be applied:
Divide yd3/1,000 ft2 by the conversion factor 3.086
Or
Divide 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 recommended
compost application rates for turf are higher than the agronomic rates, because of the higher economic value
of turf and, depending on its use, the greater potential for compaction by people walking or playing sports on
yards or athletic fields. For restoring degraded land, the recommend rates for compost additions can be as
high as 250 cubic yards or 84 tons per acre, especially when the natural topsoil is missing (5).
//SUSTAINABLE TURF CARE PAGE 5

6. they are actively growing. These grass species
should not be fertilized in the fall or winter when
they are dormant (13, 14).
Turf species, soil conditions, length of the grow-
ing season, and cultural practices all affect the
amount of nitrogen fertilizer required. In gen-
eral, cool season grasses such as Kentucky blue-
grass, fine fescue, tall fescue, and perennial
ryegrass require 2 ½ to 3 pounds of N per 1,000
square feet (109–130 lbs./acre) per year, while
warm season grasses such as bahiagrass and
bermudagrass require 5 to 10 pounds of N per
1,000 square feet (217–435 lbs./acre) (13, 15). Turf
needs more nitrogen in southern states, where
the growing season is longer, compared to north-
ern latitudes where the growing season is
shorter.
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 correct
either be dissolved into solution by organic ac- amount of nutrients without risking contamination of the environment
ids or mineralized by microbial activity prior to (Photo by Lynn Betts, Natural Resources Conservation Service)
becoming available before they are available to
plants, several weeks may pass before turf grass
responds to initial applications of compost. An- Soil pH refers to the acidity (soil pH lower than
nual or semi-annual applications of compost will 7) or alkalinity (pH greater than 7) of a soil. Most
eventually provide a continual release of nutri- turf grasses thrive best at a near neutral pH of
ents 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 also
slow 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, and
may 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 is
or synthetic nitrogen sources. impaired. At a high pH, the micronutrients iron,
manganese, and boron become unavailable for
Natural nutrients sources. While compost is an plant uptake.
excellent natural nutrient source, its balance of
nutrients 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 combination
ent 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 lower
tive Soil Amendments and Sources of Organic Fer- soil pH, add sulfur, typically available in the form
tilizers and Amendments, respectively. of the mineral gypsum.
PAGE 6 //SUSTAINABLE TURF CARE

7. The nitrogen in topdressed fertilizers is subject This is particularly true for compost made from
to 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 nutrients
plant growth (16). Incorporating compost or fer- against leaching and runoff (18).
tilizer into the soil can decrease the chances for
volatilization. As will be discussed in more de- Soluble nitrogen applied through an irrigation
tail below, core aerating the soil prior to apply- system has less potential for leaching than if it is
ing compost allows it to fall into the aeration broadcast or topdressed on the sod, since only
holes and become partially incorporated into the small amounts are added to the soil with each
soil. 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, and
not to overapply nitrogen to turf. Large doses of compost teas. Synthetic slow-release nitrogen
soluble nitrogen can injure or kill both plants and fertilizers, such as sulfur coated urea or resin- and
soil 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 contaminate
less injurious to turf than ammonic forms. Im- groundwater than are soluble fertilizers.
mature compost or other materials with a high
nitrogen 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 wetlands
terials can cause seedling death (16). High ni- can collect and treat nutrients and sediments
trogen availability also increases the succulence from storm water runoff. These areas also can
of turf grasses and their susceptibility to attack provide flood control, wildlife habitat, and a
by pests and diseases, including chinch bugs, sod source of irrigation water (14).
webworms, parasitic nematodes, and brown
patch. 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. Applying
too much fertilizer or providing turf with nutri- People walking, exercising, or playing on the
ent applications that are out of balance with the grass can compact turf soils. Even mowing the
nutrient needs of the turf can cause water pollu- lawn can compact the soil, especially if the soil is
tion problems. The average homeowner uses ten moist or wet when it is mowed. Applying high
times more chemical fertilizers per acre than rates of nitrogen fertilizer (especially ammonic
farmers 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 the
ground 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 of
izers can result in phosphorus runoff, which con- the natural characteristics of the soil in the area
tributes 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. 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 of
nutrient-poor and easily compacted clay subsoil.
Thatch. Thatch is turf root growth that forms on
the surface of compacted soils. Lawn clippings
do not form thatch. In fact, if managed prop-
erly, they can help break down thatch. Thick
thatch contributes to soil compaction and hin-
ders water infiltration, soil aeration, and the
growth of soil organisms. Over fertilization and
over watering causes a thick thatch to build up.
http://www.usa.husqvarna.com/node1269.asp
On smaller yards or in yards where thatch is built
up in isolated areas, raking can loosen it. You A professional aerator.
can leave this loosened thatch on the lawn to
decompose or add it to your compost pile. Larger heavier mixture that will fall into the holes more
yards may require a mechanical dethatcher. readily. The compost stimulates the activities of
However, large dethatchers can be very destruc- earthworms and soil microbes that break down
tive to turf and the soil structure. Many turf pro- excess thatch, form soil aggregates, and create
fessionals prefer using management practices tunnels through the soil. As biological activity
that encourage natural thatch decomposition by in the soil increases, mechanical aeration may no
earthworms. Regular applications of compost, longer be required. Instead, biological aeration,
combined with soil aeration, provide earthworms stimulated by regular surface applications of
and other soil organisms with the air, moisture, compost, may be sufficient (7, 19, 20).
and nutrients they need to grow and break down
thatch (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 contain
ity or by combining mechanical aeration with heavy metals or toxic chemicals. The type of soil
compost 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 being
the lawn or field you are treating. You can aer- compacted. If a lawn or field has very thin soil
ate a very small lawn with a garden fork, by in- and soil additions are necessary, make sure to
serting the fork 6 inches deep every 4 to 6 inches get the soil from a reputable source. If you are
and working it back and forth gently. On larger unsure of the soil quality, or you are going to
yards, you can use a mechanical, walk-behind work with a soil supplier on a regular basis, you
aerator. These machines pull cores 2 to 3 inches may want to analyze the soil for contaminants
deep. For best results, make three or more passes such as heavy metals. When adding topsoil, mix
across 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 inches
or 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 debris
post will fall into the core holes, resulting in a such as thatch, and mineralizing nutrients in turf
partial 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. nium nitrate and methyl urea significantly reduce ance in mid-summer. A mixture of appropriate
earthworm populations (21). Both pesticides and turf species also protects the whole yard against
fertilizers 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 of
mychorrhizal 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 labels
from the soil. carefully before purchasing turf grass. Inexpen-
sive mixtures often contain seeds of grasses that
In contrast to soluble fertilizers, compost contains either have weedy characteristics or are annuals
carbon and nutrients that promote the growth and need to be reseeded yearly. Common filler
of soil organisms. Making the transition from a grass varieties include annual ryegrass, orchard
chemically maintained turf to an organic or least- grass, timothy, annual bluegrass, bentgrass, and
toxic turf can reduce thatch build up and pro- rough bluegrass (22, 23). To avoid weed control
duce 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 Kentucky
Environment
bluegrass rather than just Kentucky blue
grass
Turf species. Turf composed of a single species
• Germination rate of seed —should be at
is highly susceptible to becoming weedy and
least 75% for Kentucky bluegrass and 85%
demands more nutrients and water than turf
for others
composed 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 label
conditions within the yard. Also, choose variet-
ies that are resistant to common pests in the area
A good source for comparative information on
and 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, <http://www.ntep.org/>. 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, you
provide 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 often
mixed with tall fescue or fine fescue to provide
better wear and disease resistance. In more Cool-season grasses do most of their growing
northern 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-season
conditions (19). In mid-latitude locations, a mix- grasses peaks during the two months prior to
ture of cool season and warm season grasses al- maximum shoot growth in the spring and
lows for cold tolerance at the beginning and end during the two months following the peak of
of the season along with heat and drought toler- shoot growth in the fall.
//SUSTAINABLE TURF CARE PAGE 9

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 medic
can 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. (http://www.ampacseed.com/ rainfall areas of the upper Midwest and north-
clover1.htm)
eastern United States, and southern Canada (27,
PAGE 10 //SUSTAINABLE TURF CARE

11. 28). Sedges and rushes serve as a low-mainte- of sand and compost mix (33). Then, in the
nance ground cover suitable for moist climates. spring, remove any remaining plant growth by
Genetically-modified “no-mow” grass varieties burning it or scalping the soil with a lawnmower
are also being developed. Researchers creating before planting seeds. If you wait until spring to
these 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 for
tivity of a growth hormone (29). weeds to grow, kill the weeds with a herbicide
or by flame weeding, then plant the wildflower
Wildflowers. 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 for
ety to your landscape. The diversity of species Vegetable Crops.
in wildflower lawns or meadows increases pest
and disease resistance while attracting beneficial Mixing wildflower seed with an annual cover
insects 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 such
shade, and moisture conditions. And since wild- as buckwheat, annual flax, wild rye or oats, or
flower 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 are
to-manage areas (30, 31). appropriate for the upper Midwest, while purple
three-awn and Mexican hat are suitable for the
Choosing seed. To ensure that a wildflower South or Southwest (28).
planting will thrive, select wildflower mixtures
that are either native to or well adapted to the Since many wildflower seeds are small, you have
local climate and soil conditions. Note that many better control over their distribution if your mix
non-native, naturalized species, including Queen them with compost, potting soil, or sand before
Anne’s Lace, chickory, Dame’s Rocket, Ox Eye broadcasting. Attempt to plant approximately
Daisy (Shasta Daisy), Bachelor’s Button (Corn fifteen to thirty seeds per square foot. This will
flower), and Butter and Eggs, are used heavily ensure that there are enough plants to crowd out
in most commercial wildflower seed mixes be- weeds without the wildflowers being so close
cause 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 wildflower
area is often difficult to produce from seed be-
cause many home owners or lawn managers are
unable to distinguish weeds from desirable
plants when the plants are still small. While fall
planting allows for earlier blooming of flowers
in the spring, spring planting allows for better Illustration 4. Wildflowers add diversity to lawns. (Photo
weed 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 of
since it can destroy seeds of prairie species lay- seed, much of this seed will probably not fall on
ing 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 a
is to first smother the existing turf over winter balance between annuals and perennials, as well
under layers of newspaper held down by a layer as decrease the potential for weed competition.
//SUSTAINABLE TURF CARE PAGE 11

12. Grasses, especially native warm-season prairie
grasses, are a natural complement to wildflow-
ers. The grass species little bluestem (Andropogon
scoparius), sideoats grama (Bouteloua curtipendula),
and indiangrass (Sorghastrum nutans) are excel-
lent companions for wildflowers since they grow
readily 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 — http://www.americansod.com/photoessay.html
grow 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 to
Illustration 5. Prairie grasses can add diversity and beauty
the soil. However, inorganic mulches, such as
to 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. Thick
To rapidly establish a wildflower area, you can mulches hinder air and water movement through
purchase 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 Stress
flower sod costs considerably more than seeds on Turf
or mats, but this method is probably the most
labor 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 the
of 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 watering
flower sods or mats that have the greatest po-
practices that stimulate rather than stress plant
tential 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 to
environmental 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. eases, promote weed growth, and encourage that are returned to the soil, rather than being
thatch build-up. collected and bagged, replenish organic matter
and can annually add between 2 to 5 pounds of
Reducing 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 they
of 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 inches
can 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 grass
the grass is removed each time you mow. This is cut at an appropriate time and height. When
moderate trimming helps stimulate root growth choosing a mower, be careful to get a model that
without significantly reducing the leaf area avail- is able to cut to a 2 ½ to 3 inch height, since many
able for photosynthesis. reel mowers are not adjustable.
Increasing the mowing height is particularly Mower maintenance. Maintaining sharp mower
important when turf is under stress by heat, blades enhances mowing efficiency, reduces
drought, or shade. Do not leave your mower set stress on grass, and facilitates decomposition of
at the same height all year—or even while you grass clippings. Sharp mower blades also reduce
are 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 by
height to reduce stress on turf growing in the as much as 22 percent (14). Conversely, a dull
shade and when you mow during the summer blade favors the spread of diseases since it cuts
heat. 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 clean
should 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, or
This may mean mowing shady sections of your after eight hours of mowing (12).
lawn at intervals different from those used in
sunny areas. By increasing your mower height, Water management. Healthy lawns that are well
you 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 movement
a height of 7 inches or more, then mowing it to a to plant roots, while organic matter acts as a
height of 2 inches or less just before the summer sponge, absorbing water and holding it for use
drought. 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 roots
Mower 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 promote
them down into the turf. This provides a lawn turf growth over weed growth, since many turf
with a clean appearance while encouraging rapid grasses develop a deep root system, while many
decomposition of the clippings. Grass clippings weeds have shallow roots (36).
//SUSTAINABLE TURF CARE PAGE 13

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 throughout
Most grasses are adapted to seasonally dry con- the hottest days of summer, water the grass
ditions 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 provide
waterings. For best turf growth, wait until the heavy waterings as needed. You can test soil
soil has dried to a depth of 2 to 4 inches then moisture by feeling the top 2 to 4 inches of the
irrigate to replenish the water to the depth of the soil to see whether it has become dry, or you can
root 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 agricultural
If you do not pre-wet the soil, you will loose colleges. Applications of seaweed extract can
water and soil nutrients to runoff, since dry soil further reduce heat stress in turf. By stimulating
is water repellent and does not allow good wa- antioxidant production, the natural hormones in
ter 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 bare
Watering 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 replace
soil, and the flow rate of your irrigation or sprin- inappropriate or disease-prone varieties with
kling 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 the
than 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 done
lawn and may cause water pollution if it runs either in the spring (April or May) or in the fall
into storm sewers or creeks. (September or October). Prior to broadcasting
seed into the existing turf, make a pass over the
Overwatering. Watering grass too frequently or area to be overseeded with an aerator or heavy
too lightly causes lawns to develop shallow root rake. Or you can plant seed with a slice-seeder.
PAGE 14 //SUSTAINABLE TURF CARE

15. These techniques provide the conditions for good overfertilization, choosing locally appropriate
seed-to-soil contact. Seed can be broadcast or and disease resistant turf species, and mowing
planted alone, followed by a topdressing layer and irrigating correctly are practices that reduce
of compost. If turf seed is broadcast planted, it turf stress while also reducing the potential for
can be mixed with compost, and the two can be pest and disease infestations. Cultural control
broadcast together onto the prepared turf (19, 23). measures, such as using a diversity of species and
Following seed planting, press the seed into the removing disease-infested leaf litter from the
soil with a roller or, for small renovation patches, lawn, also help prevent pests and diseases from
by 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 good
cool season grasses thrive in the fall and into part ways to protect your turf.
of the winter. Under these conditions, you can
maintain 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 the
nial 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. Personnel
the fall and continue growing in the early spring.
at your local Cooperative Extension office should
Then it will die out when the warm season
also be able to help you identify and treat turf
grasses reemerge in late spring.
pest problems.
Biointensive Pest Control Methods Turf diseases. Prevention is the key to disease
for 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 biologically
vent 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. Cultural control practices for turf grass disease
control 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 http://www.bethelfarms.com/
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 that
are 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 and
Pest and disease control with compost. In addi- other microorganisms that help form humus and
tion 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 the
pressed some soil-borne fungal diseases just as available nutrients have been used is biologically
well as conventional fungicides. This effect inert and unable to suppress diseases (4, 16, 39).
lasted about thirty days, but was lost by sixty
days 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 either
Characteristics 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, while
post 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. Different composts provide selective control of
some diseases. For example, composted sewage
sludge increased the incidence of Fusarium on
carnations and peas, but decreased the incidence
of Fusarium on cucumbers (40). Composted poul-
try litter provided 75% control of brown patch
but only 15% control of typhula blight, while
composted brewery sludge provided only 25%
control of brown patch but 70% control of
typhula blight (40). Studies by Elaine Ingham
and her coworkers (42) indicate that compost
made 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 Diver
materials favor high bacterial populations. In
contrast, compost made from woody materials,
straw, and dry leaves favors the growth of fungi Microbial fungicides. If preventative measures
and 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 control
mature compost monthly. Applications of pesti- several diseases, including brown patch (caused
cides or highly concentrated soluble fertilizers by the pathogen Rhizoctonia solani), dollar spot
will disrupt or kill beneficial soil organisms and (caused by Sclerotinia homoecarpa), and pythium
minimize the effectiveness of the compost. A root rot and blight (caused by Pythium
topdressing 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 BINAB
sand, then incorporated into the soil with an aera- Bio-Innovation AB, a Swedish company, and
tor 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 and
Compost tea. You can make anaerobic compost remedial treatments of turf diseases. Studies
tea by soaking a burlap bag full of compost in a conducted at the Rutgers Center for Turfgrass
barrel 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 summer
70° F provides the highest level of disease sup- patch (45). A new anti-fungal strain of bacteria
pression (8). Aerobic compost is prepared in the labeled as APM-1 is being developed for turf use
same manner, except that the ratio of water to by researchers at the New England Turfgrass
compost 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 horticultural
Both anaerobic and aerobic compost extracts pro- plant diseases, see the Agrobiologicals Web page
tect against plant diseases (43). Research exam- (<http://www.agrobiologicals.com/>). This
ining 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 the
For this study, compost tea was applied weekly companies selling them.
to bi-weekly at the rate of one gallon per 1000
square feet (44). For more detailed information Turf insect pests. While pesticides kill insect
on the production and use of compost teas, see pests listed on their labels, many pesticides are
the ATTRA publication Notes on Compost Teas. non-specific. That is, they kill beneficial insects
//SUSTAINABLE TURF CARE PAGE 17

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 endophytes
aggregates, and suppress diseases. As a result, (see below).
pesticides may decrease insect infestations in the
short term, but create other conditions that in- To effectively control turf pests, it is necessary to
crease turf stress. Thus, turf managed with pes- correctly identify the pest and understand its life
ticides often has more pest problems and requires cycle. The Resources section of this publication
more intensive management than turf managed lists books that provide detailed descriptions of
with 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—
http://www.bethelfarms.com
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 substances
measures 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 soaps
PAGE 18 //SUSTAINABLE TURF CARE

19. Biological insecticides need to be handled and and decrease infestations from weeds, make
applied 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 is
shipped affect the viability of the organisms (48). Mowing to control weeds. Raising the mower
In addition, soil conditions at the time of appli- height reduces the incidence of some common
cation 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 3
insect-eating nematodes survive best in moist, inches, especially during the spring, provided as
loamy 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 stress
high pressure, you can apply these biological on the turfgrass and they were able to choke out
control organisms using a sprayer or irrigation the crabgrass.
equipment (49). The ATTRA publication
Biointensive Integrated Pest Management provides Mowing at a lower cut during seed set can help
detailed information on biological control prac- control annual bluegrass, crabgrass, goosegrass,
tices. It also contains extensive lists of suppliers foxtail, barnyardgrass, fall panicum, and
for biopesticides and microbial pest control dallisgrass. This technique must be carefully
agents. timed to coincide with early seed set. Attach a
clippings bag to the mower to collect and remove
Table 6 (see Appendix) summarizes cultural and seed heads. Also be careful not to mow so low
biological control measures for common turf in- that you stress the desired turf species (4).
sect pests.
When not mowing to collect and remove seed
Turf 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 of
ested 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 and
natural lawn, white clover is an integral compo- growth of certain weeds (4, 47). Many tur grass
nent of the turf. For people wanting a pure grass roots also produce allelochemicals that suppress
lawn, white clover is a weed. Using good turf the growth of weed seeds. Raising the mowing
management practices that favor the growth of height favors root growth and the production of
desired species allows these plants to out-com- these allelochemicals.
pete undesired species. Essential management
practices 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. University
weather, and management conditions that favor of Iowa turfgrass researcher, Nick Christians has
the growth of weeds. To reduce stress on turf compiled a list of suppliers of corn gluten meal,
//SUSTAINABLE TURF CARE PAGE 19

20. which is available at: turf growth and reduces the potential for dis-
<www.ipm.iastate.edu/ipm/hortnews/1997/ eases. Similarly, watering infrequently—but to
6-20-1997/cornglut.html>. the depth of root penetration—minimizes both
turf stress and the environmental conditions that
Vinegar has recently gained attention as an ef- favor root diseases. A diversity of species within
fective natural post-emergence herbicide. It a lawn reduces insect and weed infestations.
works by degrading the waxy cuticle layer on Natural lawns including clover, wildflowers, or
weed leaves, resulting in desiccation. More fre- groundcovers that are drought or shade tolerant
quent 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 typically
contains approximately 5% acetic acid, distilla- Acknowledgements
tion can increase this concentration to 15%, and
freeze 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, and
search Service demonstrated that vinegar at 10, many of the organizations and resources listed
15, or 20% acetic acid concentrations killed 80 to in this publication were taken from this earlier
100% of giant foxtail, common lambsquarters, publication. ATTRA specialist Steve Diver iden-
smooth pigweed, and velvetleaf (53). Some gar- tified compost and compost tea references, while
deners have seen increased effectiveness by add- ATTRA specialist Rex Dufour provided pest and
ing 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 organic
Like 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 in
acre for 20% acetic acid and $99.00 per acre for this publication.
30% acetic acid (54).
Organizations
While vinegar readily degrades in the soil and
has no long-term impact on soil organisms (soil
Golf Course Superintendents Assoc. of America
pH decreases at the time of application but re-
1421 Research Park Dr.
turns to its original level in less than two days),
Lawrence, KS 66049-3859
it is caustic. When applying this material, you
Telephone: 800-472-7878, 785-841-2240
should wear a mask to avoid inhalation and
http://www.gcsaa.org
gloves 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, includes
A 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, water
nating conditions that put stress on the turf. A saving practices, and compost use in golf course
soft, 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 International
control of pests and diseases. Regular additions 1855-A Hicks Rd.
of mature compost enhance soil quality while Rolling Meadows, IL 60008
providing biological control of diseases and cer- Telephone: 800-405-8873, 847-705-9898.
tain weeds. Raising mowing height to 2 ½ to 3 FAX: 847-705-8347
inches, keeping mower blades sharp, and return- E-mail: info@TurfGrassSod.org
ing mower clipping to the soil stimulates healthy Web page: http://www.TurfgrassSod.org
PAGE 20 //SUSTAINABLE TURF CARE

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 Care
National 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 necticut
Beltsville, MD 20705 PO Box 3
Telephone: 301-504-5125 Northford, CT 06472-0386.
E-mail: kmorris@ntep.org Web page: <http://www.ctnofa.org/>
Web page: http://www.ntep.org/contact.htm 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 of
United States Golf Association Green Section an organic lawn?
P.O. Box 708
Far Hills, NJ 07931 Organic Lawn Care
Telephone: 908-234-2300 Bruneau, A.H., Fred Yelverton, L.T. Lucas, and
USGA Publications: 1-800-336-4446 Rick L. Brandenburg. 1997. Publication AG-562.
Web page: http://www.usga.org/ 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 and
NOFA Accredited Organic Land Care Profes- diseases, and recommended cultivars and plant-
sionals ing dates for North Carolina.
c/o NOFA Connecticut
PO Box 386 Handbook of $uccessful Ecological Lawn Care
Northford, CT 06472-0386 Sachs, Paul D. 1996. 290 p.
Web page: http://www.organiclandcare.net/ Edaphic Press
professionals.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