Lawn pests fall into one of four categories: 1) weeds or other plants competing with the grass for resources, 2) insects feeding on the grass, 3) plant diseases, and 4) small animals digging up grass to feed on insects or plants.
Any of these can be found in your lawn, but they only become pests if conditions change to favor their increase. Prevention is the best approach for managing pests. This includes many of the cultural practices described for the establishment and for lawn maintenance. If a lawn is kept healthy using good lawn maintenance practices, it will be less susceptible to pest damage and usually will not require pesticides.
Lawn Pest Management – Lawn pest problems should be managed by following Integrated pest management (IPM) principles. IPM puts the emphasis on prevention, looks at all available information and considers all management options before deciding on the most effective, environmentally friendly and cost effective means of managing a lawn pest problem.
Lawns should be checked regularly to detect pests and other problems early. Make sure that pest problems are identified correctly. Beneficial insects may be mistaken for pests. Also, plant damage may not be caused by pests. Plants can be injured by poor growing conditions, poor maintenance practices, or environmental problems such as road salt of pet urine. The life cycle of pests needs to be identified to help decide when to apply treatments and how to prevent further problems. Once a pest in a lawn has been identified, it must be decided whether the amount of damage requires action. A few weeds or insects in a healthy lawn may not be a cause for concern. Recurring pest problems are often a sign that lawn care practices need to change.
1) Weeds: Healthy lawns are less susceptible to weed problems. They smother weeds and also prevent their seeds from germinating. Before resorting to herbicides, the general conditions of the lawn should be improved by aerating, over seeding and occasionally weeding by hand if you have sensitive plants or a vegetable garden and are worried about spray drift. Tolerating some weeds is a no-cost, no-effort alternative to weed control. Weeds could be a bigger problem in a newly seeded lawn that has not yet established a vigorous stand. Good planning and soil preparation will minimize weed problems and promote quick establishment of the lawn.
2) Insects: In a healthy lawn, beneficial insects can keep pest insects in check. Ants are sometimes considered pests because they make visible mounds (ant hills) on lawns. They do not attack the grass. Some common insect pests found in lawns include: chinch bugs, white grubs, and sod web-worms. Chinch bugs prefer dry lawns with excessive thatch. Adult beetles, the source of white grub infestations, prefer sunny south-facing slopes where it is hot and dry. Sod web-worms prefer sunny south-facing slopes where it is hot and dry.
3) Diseases: Lawn diseases can be difficult to identify and are often confused with other problems such as poor growing conditions, damage from fertilizer burn, dog urine or road salt. Some of the diseases that may occasionally affect your lawn include powdery mildew, necrotic ring spot, dollar spot, leaf spot and rust.
Good mowing and watering practices as well as using a balanced fertilizer with adequate potassium levels and not too much nitrogen help to prevent lawn diseases. If you’re not too sure about what action a specific problem requires, call a professional lawn maintenance or lawn care company for help.
Fairy rings – Fairy rings are circular or semicircular patches of dead grass with an inner green ring. They usually appear in lawns 5 to 15 years old and can be caused by a number of different fungi. The fungus feeds on thatch, and the ring grows outward. The fungus is not toxic to the grass, but it prevents water from penetrating into the grass root area causing the grass to die and allowing weeds to take root and infest that area. Fairy rings are difficult to control. To slow their spread, poke holes in the grass surface just outside the dead ring using a garden fork, soak with soapy water and water frequently to increase moisture. To get rid of the rings completely, cut out the dead patch. Re-seed or re-sod the dead areas.
4) Animals: Avoid problems with animal pests by eliminating potential food sources around your yard.
Moles and voles – small animals like moles and voles sometimes tunnel in your lawn in search of food. Tunneling by moles exposes root systems, then voles and other rodents move in and eat the roots.
Raccoons and skunks – Raccoons and skunks generally dig up your lawn looking for white grubs and other insects. Once insect pests have been managed, raccoons and skunks should no longer bother your lawn.
A note on Pesticide Use – Pesticides include herbicides for weeds, insecticides for insects and fungicides for diseases. Their labels provide specific use instructions and describe the conditions in which they can be applied. Most lawn pesticides do not prevent pest problems. They can only control pests once they are present.
Minimize the use of pesticides; keep your lawn healthy, use spot treatments rather than broadcast applications, only treat the problem area or plants, and time applications correctly to avoid the need for repeat treatments. That will depend on the susceptible life stage of the pest and environmental conditions.