Grass With Grubs

Take insects found in your lawn to your local extension service.

Keeping grass thick and green requires the right blend of vigilance, knowledge and proper tools. Many conditions plague lawns, and grass with grubs is just one of them. A healthy, thick, green lawn is achieved through proper feeding, watering and regular maintenance including insect control.

Verify Grubs

Most lawns have grubs in them each year in early August when beetle eggs hatch. A few grubs scattered throughout the lawn don't cause much damage. However, large number of grubs eating grass roots interrupts the plants' ability to take up water and nutrients, turning turf yellow and then brown. Many turf conditions have the same symptoms. Check for grubs by lifting a section of the browned turf and turf in surrounding areas. Look in the soil for plump, white or gray. C-shaped worms with large, round, brown heads and pairs of short legs. A large grub concentration threatens your lawn. The absence of grubs indicates browning has another cause.

Insecticide

For severe infestations of grubs killing large areas of turf, insecticide application is the fastest way to save the lawn. Beetles are attracted to well-watered or over-watered turf for their egg laying in midsummer. If there is a large population of June bugs in your area and you see lawn browning, check for grubs and treat the lawn with a grub-killing insecticide that contains imidacloprid.

Natural Controls

Insecticides require care in application, as they may persist in lawns where pets or children play. Nontoxic grub control options are available. Natural controls for lawn grubs include deep aeration with either aerating spike sandals or a lawn-aerating machine. Aeration spikes work best when the aeration is done close together rather than with a lot of space between perforations. Nematodes are another option. Nematode applications must be watered in to be effective.

Prevention

Grub prevention starts with beetle control. Beetle traps set out in the yard at close intervals and changed frequently as they fill, prevent beetles from laying eggs. Beetles are attracted to lush, moist lawns, so cutting back on irrigation during beetle season in July makes your turf less attractive to them.

References

• "Black & Decker The Complete Guide to a Better Lawn: How to Plant, Maintain & Improve Your Yard & Lawn"; Chris Peterson; 2011
• "Fundamentals of Turf Grass Management"; Nick Edward Christians; 2007
• "The Lawn Bible: How to Keep It Green, Groomed, and Growing Every Season of the Year"; David R. Mellor; 2003
• University of Illinois Extension; Major Turf Insects & Diseases; Bruce Spangenburg
• University of Illinois Extension: White Grubs in Lawns