Common Lawn Problems and How to Fix Them

The best way to solve lawn problems is prevention through regular watering, mowing, fertilizing, aerating, and dethatching. If you're unsure of the cause, consult a local nursery, Cooperative Extension Office, or hire a professional. Here are common issues:

Gasoline Spills or Dog Urine

Round dead patches can result from gasoline spills (filling mower on grass?) or dog urine. Leach the area thoroughly with water, gently rake away dead grass. If the patch doesn't fill in, reseed or resod.

Uneven Fertilizer Application

Dead or yellow patches may stem from uneven fertilizer. Correctly fertilized areas turn dark green; under-fertilized are pale green or yellow; over-fertilized burn brown. Remove dead patches, water well, and reseed or resod if needed.

Chinch Bugs

These 1/4-inch gray-black insects suck juices from grass blades, causing brownish-yellow patches, primarily in St. Augustine and zoysia grasses (sometimes bluegrass and creeping bentgrass), especially in hot, drought-stressed conditions. To diagnose, sink an open-ended can into the ground at a patch edge, fill with water; chinch bugs will float. Keep area well-watered to minimize spread. Chemical controls include chlorpyrifos and diazinon.

Sod Webworms

Not worms but small, hairless gray caterpillars—larvae of tiny buff-colored moths seen flying low in evenings. They feed on grass blades, causing small dead patches in spring that enlarge in summer. Diagnose by drenching an area near dead spots with 1 tablespoon liquid dish detergent in 1 gallon water; larvae surface. If more than 15 larvae per square yard, treat. Chemical controls: chlorpyrifos or diazinon. Non-chemical: improve lawn care—avoid overwatering/overfertilizing, maintain regular dethatching and aeration.

White Grubs

Catchall name for soil-dwelling larvae of beetles (June bugs, rose chafers, Japanese beetles). They feed on lawn roots, are white with brown heads, curl into a C-shape when exposed. Signs: irregular brown patches, most severe in late summer; dead patches pull up easily. Dig into soil; if more than one grub per square foot, treat. Correct identification helps choose treatment; take samples to a nursery or Extension Office.

Fairy Rings

Small circular patches of dark green grass surrounding dead or light-colored grass; mushrooms may appear at the perimeter. Caused by fungal disease in soil high in organic matter. Control: aerate soil, apply nitrogen fertilizer formulated for lawns, keep lawn wet for 3-5 days.

Rust

Fungal disease affecting primarily bluegrass and ryegrass. Blades turn yellowish to reddish-brown; small reddish pustules form on older blades and stems; blades eventually die. Solution: apply nitrogen fertilizer for lawns, water regularly, mow more frequently.

Weeds

Weeds from the garden often invade lawns. A healthy lawn with thick grass stems resists weed seeds. Poor condition and exposed soil invite weeds. Wrong grass choice (e.g., shade-intolerant grass in semishade) leads to sparse turf and weed invasion. Some warm-season grasses (Bermuda, zoysia) can become weeds if introduced into a different lawn type. Controls for Bermuda also work on zoysia. Other common lawn weeds: common mallow, crabgrass, dandelion, oxalis, plantain, quack grass, spotted spurge.