How to Prevent the Top 10 Lawn Pests and Diseases

Learn how to identify and prevent the top pests and diseases that may be harming your lawn.

Filed under: Lawn Care, Garden Pest

Lawns can become vulnerable to pests and diseases for many reasons, including restricted air movement, poor drainage, a lack or excess of nutrients, and incorrect soil pH. There are also some grass species that are more susceptible, and some weather conditions that are simply more favorable for attack.

Prevention is better than cure, and with limited chemical treatments available to the amateur it is best to try to reduce the risk of pest and disease attacks wherever possible. Regular mowing keeps the grass healthy and strong, while removing the clippings helps to prevent a build-up of fungal spores. Avoid high nitrogen feeds during the fall — this encourages long, lush growth that is more susceptible to snow mold, rust, and other fungal diseases.

1. Slime Mold

Commonly found in late summer and fall, slime molds don't actually cause harm to the grass, although they are unsightly and unpleasant if sat on. There isn't a cure for the problem, although regular aeration and scarifying reduce the risk of most fungi on the lawn. They can be removed immediately by spraying with a jet of water.

Slim Mold Disease Can Attack Healthy Lawn

2. Red Thread

Probably the most common lawn disease, red thread causes patches of red-tinged grass, which turn brown and die back. It is often associated with nitrogen deficiency, so feed the lawn with ammonium sulfate as soon as symptoms are spotted; it is usually worst after wet summers and falls. Regularly aerate and scarify to improve air circulation.

3. Rust

This disease can spread rapidly through a lawn, creating yellow patches. Up close, rusty orange pustules can be seen on the grass blades. No chemical control is available, but regular mowing and the removal of clippings will prevent it from spreading. Avoid using high nitrogen fertilizers in the fall. This can cause lank growth, which is more susceptible to disease.