There is a small window of time at the end of July and the beginning of August when grubs are most easily killed. If you haven’t gotten your grub treatment down yet, don’t wait. In a few weeks, you’ll see the damage, but by then it will be too late the damage has been done. This year, the hatch of the 2010 brood is estimated to be the weeks of July 25th -Aug. 5th, based on peak flight of the adult beetles that occurred around June 25th, according to the Kansas State University Entomology Department.
This is the time of year that the grubs emerge from their eggs and burrow up into the top layer of soil where they eat the roots of the grass. They are easiest to kill in this early stage of development. In early fall, the grubs will begin to burrow four to eight inches into the soil away from the cold. They will return older and hardier in the spring and will cause more damage then.
White grubs in lawns are the larvae stage of common beetles like the June bug and the Black Masked Chafer. These root eating larvae are found throughout Kansas and are a perennial problem in lawns in the Kansas City area. We generally don’t see damage from grubs until the end of August or first of September because they feed on the roots you can’t always tell they are there until the damage is done.
If you notice brown patches in your lawn that look a lot like drought stress, you may have grubs. Because the grubs feed on the roots, the grass begins to die and the ground will feel soft or spongy. The green grass next to the damaged areas may lift up just like carpet.
You can check to see if you have grubs by digging up an area that’s showing signs of grass browning. Dig a one foot by one foot area of your lawn to just below the roots. Pull back the turf in these suspect areas, in particular the marginal areas where brown grass meets green grass, and look for the grubs. Usually a population of about 10 or more grubs per square foot will lead to browning of the lawn.
Another sign of grubs is damage from skunks and raccoons digging up lawns in search of grubs to eat. This usually happens at night. Moles may or may not be feeding on grubs so are not a reliable indicator of grub problems.
If you suspect you have a grub problem the important thing is to do something about it in the next few weeks. That’s when they’re the most susceptible because they are near the surface. Once they burrow down 4 – 8 inches, they are out of reach out to a specialist for Heritage Lawn’s pest control services in Westport, Olathe, Brookside or where ever you may live in the Greater Kansas City area. Call us if you suspect grubs and we can confirm your diagnosis, treat if needed, and start helping your lawn recover.