Grubs Are in My Centipede Lawn Grass

Centipede grass is a warm season turf used for its drought tolerance, ability to grow in acidic soil, medium texture and low need for maintenance. Unfortunately, grubs can infest centipede grass and cause a host of problems. In fact, centipede grass can show signs of grub damage in the spring and summer that is so expansive that the entire lawn must be renovated. Gardeners should determine the extent of their grub infestation to pick what kind of treatment to use.

Grubs

Grubs are beetles in the larval stage that have hatched in the soil of your centipede grass. There are numerous types of beetles that lay eggs in the yard, including May beetle, June beetles, Japanese beetle and northern masked chafers, according to Pennsylvania State University Extension. Beetles start laying eggs in the late summer. During winter, the larvae burrow into the top 2 to 8 inches of soil and rise when the soil warms up in the spring.

Damage

Grubs inflict damage by eating away at your centipede grass's root systems. Typically, you will see browning or wilting in irregular patches in the yard, according to the University of Illinois Extension. Often, gardeners can mistake grub damage for other lawn problems. For instance, centipede grass has a fair tolerance to shade. If the grass is planted in an area that receives full shade, it may exhibit bare areas or thinning areas that look like grub damage.

Testing

Test the extent of your grub problem by cutting out 1 square foot of centipede turf that is 2 to 4 inches deep. Count the number of grubs that you see in the soil, within the thatch or in the grass. Thatch is the brown spongy material between the grass blades and soil. If there are fewer than 10 grubs in the grass sample, you can allow the grass to dry out. Dry turf will cause the eggs to die out in the hottest part of summer, according to Pennsylvania State University Extension. Ten or more grubs in a square foot area will require pesticide use.

Chemical Control

Use a pesticide spray that contains halofenozide or imidacloprid to help control your grub problem. Avoid applying the pesticide on water-stressed centipede grass. Give your centipede grass enough water to absorb into the first 4 to 6 inches of topsoil, according to Texas A&M University. Apply the pesticide to the lawn and water the pesticide into the soil. If you don't water the pesticide into the soil, it will never get to where the grubs live. Reapply the pesticide according to the directions.

References

• Texas A&M Cooperative Extension; Centipedegrass; Richard L. Duble
• University of Illinois Extension; White Grubs in Lawns; Bruce Spangenberg
• Pennsylvania State University College of Agriculture; White Grubs in Home Lawns; Paul Heller; May 2006
• Clemson University Extension; Selecting a Lawn Grass; Bob Polomski and Debbie Shaughnessy; August 2003