Whether in a front yard or public park, a lush, green lawn is a welcome sight. Unfortunately, grubs can mar the look of your turf and even threaten its health. These lawn pests are beetle larvae that live just below the soil surface and feed on grass roots. The resulting damage affects the turf's ability to absorb water and nutrients, leaving unsightly brown spots.
Common Grub Damage
Grubs feed on grass roots, which causes wilted grass. This results in patches of brown turf and eventual death of the grass. Grub-damaged turf is brown and spongy and can be easily lifted off of the soil. Birds, moles and skunks also tend to be attracted to lawns with grubs. You'll see them pecking the lawn or digging around, contributing to its deterioration.
Left untreated, grub damage can become extensive. The following methods will help you get grubs under control so you can get your turf back to a healthy, lush lawn.
If the damage is in a small area, it's possible to till the soil and hand-pick the grubs. Once removed from the soil and grass, you can either kill the grubs using soapy water, or transfer them to a bird feeder.
Like hand removal, cultural controls are smart gardening methods that effectively deter grubs. Using the best cultural control helps you avoid having to resort to more extreme methods that are harmful to pets and people. This option is also environmentally friendly, and safe for other plants and flowers.
One easy cultural control is to be selective about when you water your grass. Avoid irrigating extensively in June and July, because that will attract egg-laying female beetles to the lawn. The beetles seek a moisture-rich environment to raise young. The moisture also increases the likelihood that the eggs survive. Instead, water infrequently but deeply.
If grub damage is extensive, consider renovating the lawn and replacing it with tall fescue. This type of lawn is more tolerant of grub damage than others. Thick, healthy turf also tends to ward off grubs.
When you use biological controls on pests, you treat infestations as Mother Nature would. Biological controls tend to be safe methods of treatment that aren't harmful to pets or people.
Beat back the grubs by introducing them to their natural foes: beneficial nematodes. These are tiny worms that feed on grubs by entering grub bodies and eating their insides, which liquefies them. Find the species Heterorhabditis bacteriophora and apply directly to your turf. For best results, follow application instructions carefully, including required outdoor temperature and levels of soil moisture.
Pesticides for Grub Control
If nontoxic methods fail, consider trying pesticides for grub control. Such products are toxic to animals and people, so use caution when applying.
Turf pesticides that treat grub infestations contain the active ingredient trichlorfon (Dylox) or carbaryl. Follow package directions as to how to apply pesticides. The soil must be wet for application as it encourages the grubs to move to the soil surface. Unless it recently rained, this generally means soaking your lawn prior to application.
Once you have applied the pesticide, be sure to avoid direct contact with your lawn, and keep children and pets away for as long as instructed on the package.