Grubs damage lawns by eating the roots of the grass. When grubs appear in your lawn, the damage can be extensive. How you repair the lawn can depend on the extent of the damage. The first step is to kill the grubs. Once this has been accomplished, use a few basic procedures to repair the lawn and prevent grubs from returning the following season.
Things You'll Need
Water all parts of the lawn that have undergone grub damage. Thoroughly water at least 10 minutes.
Remove grass from the lawn that was infected by grubs. Peel grass back and roll it up. Deposit damaged grass in garbage bags.
Turn over the soil with a rake or spade. Remove any grubs or grub larvae that appear when soil is turned over.
Aerate the soil with an aerating tool. Aerating improves the drainage, and allows fertilizer to get into the lawn.
Spread fertilizer over the lawn.
Water the lawn again. Grass seed stays better in soil that is moist.
Spread grass seed over the damaged part of the lawn. Use a grass spreader for large areas. Spread by hand for small patches. When using a spreader, walk in different directions to create an even distribution of seed. Spread seed into healthy grass a foot from damaged area. This will help avoid bare patches after seed grows. Spread grass seed liberally.
Use a rake to cover the seed with a thin layer of dirt. Place a layer of straw over the lawn to hold seed in place. You can also place an erosion mat over a damaged area. An erosion mat is made of a biodegradable material. The mat allows water and sun to get in while holding the seeds in place.
Water the area with a sprinkler until the new grass is fully established. Mow the grass when it reaches 3 inches. Keep the grass at a 3-inch level. Do not mow the grass too short. Remove any weeds that appear where the new grass is growing.
Ask an expert what insecticide would be appropriate for killing grub in its larvae stages. A product called Mach 2, for instance, is considered very effective at killing white grub larvae. Apply the insecticide for at least one more year in the spring.
The best time to re-seed a lawn is during the spring. Instead of seeding the lawn, you can consider laying sod. If grubs keep coming back, consult an expert to find out if a different kind of grass will be more grub resistant.
Do not water grass seed with a hose. The stream from the hose can scatter the seed.