How to Treat Grubs in Your Lawn

Overview

They may be unseen, but underground grubs are a hidden threat to your landscape. June bugs and Japanese beetles are just two of the several types of beetles that may lay eggs in your lawn. These eggs hatch in the late spring or early summer, and the resulting grubs attack your lawn's roots and create widespread yellowing, wilting or brown spots. Treat your lawn with insecticides to immediately eradicate these pests.

Step 1

Mow your lawn to the lowest height that's acceptable for your specific lawn species. This will allow your grub treatment products to effectively penetrate the lawn. Acceptable heights vary by grass type. For example, hybrid Bermuda grass can handle a height of 3/4 inches, while red fescue should be kept at 2 1/4 inches. The University of California/Davis has full recommendations on mowing heights for some of North America's most popular lawn species. Find a link in Resources.

Step 2

Treat the lawn if you count 10 or more beetle grubs in a square foot of grass. Check by using a spade to lift up the sod. Any fewer than 10 per square foot, and your lawn does not yet need a treatment.

Step 3

Treat your lawn. Spray the grass with a permethrin- or acephate-based lawn insecticide. This kills the grubs upon contact. Follow the insecticide's label for application instructions, as potency varies widely by brand and product.

Tips and Warnings

  • Wear safety gear such as gloves and eye goggles when you handle any type of insecticide or herbicide.

Things You'll Need

  • Lawn mower
  • Spade
  • Insecticide
  • Gloves and eye goggles

References

  • "The Lawn Bible: How to Keep It Green, Groomed and Growing Every Season of the Year"; David Mellor; 2003
  • "Lawns: Your Guide to to a Beautiful Yard"; Nick Christians, et al.; 2007

Who Can Help

  • University of California/Davis: Mowing Heights for Warm Season Grass
  • University of California/Davis: Mowing Heights for Cool Season Grass
Keywords: treat lawn grubs, kill lawn grubs, remove lawn grubs

About this Author

Josh Duvauchelle is an editor and journalist with more than 10 years' experience. His work has appeared in various magazines, including "Honolulu Magazine," which has more paid subscribers than any other magazine in Hawaii. He graduated with honors from Trinity Western University, holding a Bachelor of Arts in professional communications, and earned a certificate in applied leadership and public affairs from the Laurentian Leadership Centre.