The lawn is an important part of the home landscape. It provides beauty and a place for recreation around the home. Apart from aesthetics, a maintained lawn cools the air in summer and reduces erosion. Lawns reduce noise and improve air quality by trapping dust and pollutants. Lawns will also reduce surface runoff and leaching of fertilizer and pesticides.
Increasingly, the public has been concerned about the use of pesticides around the home landscape. Managing a lawn without primary reliance on pesticides can be achieved using Integrated Pest Management or IPM. IPM helps to maintain an attractive lawn while minimizing pesticide and fertilizer use. IPM does not exclude pesticide use but can reduce or, in some cases, eliminate it.
Homeowners, however, should have a realistic approach to maintaining a lawn with the use of no pesticides. There may be more weeds, an occasional brown spot or other imperfections. These types of problems can be reduced through the use of proper cultural practices. A properly maintained lawn will be vigorous and more tolerant of lawn pests in general.
IPM uses a variety of methods to control pests and maintain plant vigor. Some of these methods include proper seed selection, correct cultural practices, biological controls, weather monitoring and scouting. Pesticides are used only when these methods are unsuccessful at controlling pests and damage is evident. Precise timing and correct application of the least toxic materials is the main concern when using pesticides in IPM..
The first step to having a low maintenance lawn is to select the correct grass species for the environment in which it is to be planted. The amount of use and level of care is also a consideration when selecting the correct grass.mixture for the lawn. Selecting cultivars that are disease, insect and drought resistant is also important.
The four major cool-season grasses for home lawns in Connecticut include Kentucky bluegrass, perennial ryegrass, fine leaf fescues and tall fescue. Kentucky bluegrass and perennial ryegrass require high maintenance such as regular fertilizing and adequate water. Fine fescues are a group of fescues including chewings, creeping red and hard fescues. Fine leaf fescues perform well under low maintenance situations and should be considered for use when looking for a low maintenance lawn grass. Tall fescue is another lower maintenance grass but does not perform as well as the fine fescues under very low maintenance.
The soil should be tested to determine limestone and nutrient recommendations. Soil testing information ran be obtained from any University of Connecticut Cooperative Extension Center. Maintaining a soil pH between 6.0 and 7.0 makes nutrients most available to the grass plants. Limestone can be applied to raise soil pH, based on soil test recommendations.
Slow-release or water-insoluble fertilizers, such as sulfur-coated urea, polyon-coated fertilizer and natural organic fertilizers, are recommended for use on home lawns. Slow-release fertilizers are less prone to leach, applied less frequently and less likely to burn the lawn. Quick release or water-soluble fertilizers provide the consumer with the instant green-up effect, but are prone to leach. These require frequent applications. Apply fertilizer two to three times annually (generally with one to two pounds of nitrogen per 1000 square feet per year), depending on the type of fertilizer and grass species present. Two fertilizer applications are usually adequate for most home lawns in Connecticut. Apply one pound of nitrogen per 1000 square feet in late spring and again in early September. If applying fertilizer three times annually, apply in early spring, late spring and early September. Late fall applications of fertilizer can leach and compromise water quality under certain conditions.
Mowing is an example of a cultural practice that is extremely effective to produce a thick, dense lawn, discourage weed invasion, and recycle nutrients. Mow frequently as to not remove more than one-third of the leaf blade at each cutting. Mow frequently when conditions are favorable for growth such as in spring and fall. Keep the mower blade sharp to lessen injury, evapotranspiration, and improve the overall appearance of the lawn. Do not mow wet grass. This can easily spread lawn diseases and cause grass clippings to clump and smother the grass. Mow selectively around dormant grass to prevent mechanical injury. Mow the lawn until growth stops in the fall.
Mowing recommendations for home lawns in Connecticut are 1.5 to 2 inches in spring and fall and at 3 inches in summer. Gradually raise the height of cut in late spring to 3 inches. After September 1, begin to gradually lower the height of cut back to 1.5 to 2 inches.
Leave the clippings on the lawn after it is cut. There is no benefit to removing the clippings. They do not contribute to thatch accumulation. Clippings recycle 50% of the nitrogen back to the lawn. Clippings also contribute to organic matter accumulation and increase earthworm activity. Also, there may be suppression of some lawn diseases when grass clippings are left on the lawn. Only remove grass clippings when infrequent mowing has produced large piles of clippings, which can smother the grass. Never use grass clippings, that have been treated with pesticides, in the compost bin. Contaminated compost can harm garden plants or be absorbed into vegetables/fruits, which can harm humans if eaten.
Plant drought tolerant grass species and cultivars to reduce water requirements. Fine and tall fescues are drought tolerant and perform better under unirrigated conditions. Check the texture of the soil. Amend sandy soils with leaf compost and composted manures to add sources of organic matter which help hold moisture.
When considering whether or not to water, the following guideline should be maintained. Water deeply and infrequently to a depth of 6 inches, with 1/2 to 1 inch of water once or twice a week. Avoid light frequent waterings, which encourage shallow rooted grass. The best time to water is from 5:00 a.m. to 8:30 a.m. Do not apply water after 9:00 a.m. which extends the time the grass blades are wet from dew or irrigation. The second best time to water is in the evening after the dew has fallen on the lawn. Do not water the lawn in the late afternoon or early evening. Avoid watering in the evening during hot, humid weather in order to reduce the spread of some lawn diseases.
Water is a precious resource, and some homeowners do not want to water the lawn. Kentucky bluegrass, perennial ryegrass and the fescues have the capacity to survive under nonirrigated conditions by becoming dormant. Dormant grass appears straw colored and does not grow. Unfortunately, dormant grass may be susceptible to injury or invasion from insects, disease or weeds. Therefore, a well-watered lawn is more vigorous and thus more resistant to lawn pests. This minimizes the need for pesticides.
There are four major insect pests found on home lawns in Connecticut. The chinch bug, sod webworm and the billbug are surface feeding insects. They typically cause damage to lawns during hot, summer months. The white grub feeds below the surface chewing on grass roots. It causes the most economic damage during the late summer and some damage in spring to lawns in Connecticut. The white grub is the immature stage of various beetle species including the Japanese, Oriental and Asiatic garden beetles and the European chafer. A well-irrigated and fertilized lawn may be able to withstand damage from these insect pests better than a thin, slow growing lawn.
The turfgrass industry has developed several species of grasses that contain an endophyte fungus. The fungus lives within the grass plant but does not harm it. In fact, the plant benefits from the endophyte because it provides resistance against foliar feeding insects. Endophytes are found in perennial ryegrass, fine and tall fescues. Kentucky bluegrass does not have endophytes associated with it. Overseeding the lawn with endophyte enhanced grass seed can help introduce a natural resistance for surface feeding insects and can help reduce the need for insecticides.
Biological control, such as Bacillus thuringiensis, is effective at managing sod webworm and cutworms when they are small caterpillars. Beneficial nematodes are also another nonchemical option for managing white grubs in late summer.
Weeds can be managed through proper lawn establishment, and correct mowing frequency and height. Renovate the lawn between August 15 and September 15 to remove unwanted vegetation. Water lightly to keep the seeding moist. When grass begins to grow, mow at 1-1/2 inches until established. Mow at 2-1/2 to 3 inches the following season to produce a thick, dense lawn cover. A dense lawn mowed up to a height of 3 inches will resist encroachment from annual and perennial grass and broadleaf weeds.
Most home lawn diseases can be managed through correct cultural practices. Mow the lawn at the correct height of cut. A shortly mowed lawn will be more susceptible to stress. Mow the lawn when the grass is dry. Mowing wet grass can spread disease across the lawn. Manage the amount and timing of a fertilizer application. Excessive nitrogen applications can encourage lawn diseases such as leaf spot, melting out, brown patch, stripe smut, pythium blight and powdery mildew. Some diseases, including red thread, dollar spot and rust, develop due to a lack of nitrogen. It is important to maintain a fertility balance to reduce the development of any lawn disease. Recycle lawn clippings by leaving them on the lawn after mowing. This helps maintain fertility and may suppress some lawn diseases.
Manage thatch and soil compaction. Thatch is the layer of dead and dying plant parts (primarily roots) between the base of the grass plants and the soil. Excessive thatch creates an excellent environment for diseases as well as for insects. Dethatch or core aerate in spring or fall to manage thatch. Core aeration in spring and fall can be used to reduce soil compaction; as well.
Lawn pests can be managed through the use of IPM. IPM begins with using correct cultural practices and other methods to produce a dense, vigorous lawn. A healthy lawn will be able to resist invasion from pests and reduce the need for unnecessary pesticide and fertilizer applications. For more information on aspects of lawn maintenance see the additional Cooperative Extension System fact sheet references listed below. University of Connecticut Cooperative Extension Horticulture Fact Sheets are available from Connecticut Cooperative Extension Centers statewide.
Fact Sheets
No. Title
13. Insects and Other Common Pests of Lawns
14. Clover Mites and Their Control
18. Moss in Lawns: Cause and Corrective Measures
23. Lawn and Shade Problems and Corrective Measures
37. Controlling Insects and Other Common Pests of Lawns
50. Thatch - Problems and Corrective Measures Lawn Construction and Maintenance
58. Lawn Construction and Maintenance
By Dana Karpowich Turf,
IPM Coordinator, University of Connecticut
Reprinted from Hort Impact, Vol. 98-6. pp. 1-3.
The information in this material is for educational purposes. The recommendations contained are based on the best available knowledge at the time of printing. Any reference to commercial products, trade or brand names is for information only, and no endorsement or approval is intended. The Cooperative Extension system does not guarantee or warrant the standard of any product referenced or imply approval of the product to the exclusion of others which also may be available.All agrochemicals/pesticides listed are registered for suggested uses in accordance with federal and Connecticut state laws and regulations as of the date of printing. If the information does not agree with current labeling, follow the label instructions. The label is the law.Warning! Agrochemicals/pesticides are dangerous. Read and follow all instructions and safety precautions on labels. Carefully handle and store agrochemicals/pesticides in originally labeled containers immediately in a safe manner and place. Contact the Connecticut Department of Environmental Protection for current regulations.The user of this information assumes all risks for personal injury or property damage.Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Kirklyn M. Kerr, Director, Cooperative Extension System, The University of Connecticut, Storrs. The Connecticut Cooperative Extension System offers its programs to persons regardless of race, color, national origin, sex, age or disability and is an equal opportunity employer.