According to Penn State University (PSU), grubs in lawns will devastate turf grass under a heavy infestation. If there is heavy grub activity on your lawn, you will see a patch of dead turf that feels spongy. The sod can be lifted from the soil like a piece of carpet. Under the sod will be small white grubs with brown heads. The grubs will be laying on their sides in the shape of the letter “C”. While maintaining a healthy lawn is the best control against grubs, pesticide applications are warranted to eliminate a heavy infestation.
Keep the lawn and turf grass dry from July to early August. The lack of moisture may dry the grub eggs and kill them. The lawn will turn brown from the lack of moisture.
Irrigate the lawn on an irregular schedule after late August. The irregular schedule will promote deeper roots in the grass, discouraging grubs from eating near the surface and destroying roots.
Apply a curative or rescue grub strategy to spots in the lawn that are actively being affected. Spot treat the infected areas with a grub pesticide. Follow label directions on the packaging. In most applications, the dry granules are spread over the area of grub infestation. Water the granules so the chemical will soak into the soil.
Create a preventive grub strategy. Treat the entire lawn with pesticide from mid-June to mid-July. Spread the pesticide granules over the lawn according to product directions. Irrigate the granules into the soil. Various pesticides will have different application rates.