Grubs on Delafield Lawns in Summer

Brown patches on Delafield lawns in summer are not always grubs—but grubs are common enough that every brown spot gets blamed on them. Shaded fence lines, drought stress, and lawn disease can look similar from a distance. Here is how to identify real insect damage before treating your whole yard.

Properties in Delafield, Pewaukee, and Brookfield often see insect damage along sunny back corners and open lawn areas where grubs feed on roots. Kanavas provides lawn care tailored to Waukesha County soils. If patches are circular with dark edges, see our summer lawn disease guide first—fungus and grubs need different treatments.

What grub damage looks like

Grubs are beetle larvae that feed on grass roots underground. Affected turf turns brown, wilts despite watering, and peels up like loose carpet when you tug. Damage often appears in irregular patches that grow outward as larvae feed. Skunks and raccoons digging in the lawn at night are a strong sign grubs are present.

A simple field check

On a dry morning, gently tug turf at the edge of a brown patch. If the sod lifts easily like a loose carpet, grubs may have eaten the roots. Cut a small square of turf and look for white C-shaped larvae in the top few inches of soil. If grass stays rooted and soil feels hard, aeration may be the better first step. Photograph what you find before treating the entire yard.

When grub control makes sense

Grub treatments follow evidence and proper timing for Wisconsin lawns—not every brown arc needs a blanket application. When grubs are confirmed, grub control paired with balanced fertilization helps roots recover after larvae are gone.

Aeration after grub damage

Once grubs are treated and roots begin recovering, core aeration helps new roots penetrate compacted clay. Time aeration when soil is moist enough for clean cores but not so wet that plugs smear—usually early fall on Lake Country lawns.

Other lawn insects to watch for

Sod webworm and billbug damage can mimic drought from a distance. Look for silk at the soil line in morning dew, or hollow stems on sunny back corners. Lawn insect control depends on identifying the pest—treating for the wrong insect wastes time and money on already-stressed turf.

Wildlife digging often points to grubs

Skunks and raccoons dig in lawns searching for grubs. If you see fresh digging at night, check whether turf lifts at patch edges—that confirms larvae are present and treatment is warranted.

Plan autumn overseeding for bare patches

Summer seeding rarely succeeds in heat. Document bare areas now and plan overseeding for autumn, after aeration, when Lake Country clay cools enough for cool-season grass to germinate.

Professional grub control in Lake Country

Kanavas has served Waukesha County since 1974. Contact us with photos of brown patches and any turf you can lift—we will help identify the cause before recommending grub control or other treatment.