Information from Colorado State University Cooperative ExtensionLittle grubs and sodworms make it their business to fill your lawn with unhealthy, brown spots. If you suspect grub damage, grab the damaged grass and give it a pull. If it pulls easily and doesn't seem to have roots attached, you likely have grub damage. If it stays firmly attached, it's probably sod wedworm or a turf disease. Use a disclosing solution to bring the sod webworms and other insects to the surface. Mix one-fourth cup of dry laundry detergent in a gallon of water and sprinkle on one square yard of lawn. The detergent will irritate the insects and they'll come to the surface in about 15 minutes. If the insects don't show themselves, you could have a disease problem. In either case, call the Colorado State University Cooperative Extension office in your county. Ask for information about turfgrass pest control.
Photo: Judy Sedbrook
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010