Identifying and Dealing with Grubs in Your Lawn

Lawn care can be a very satisfying job and yet a very complex one at the same time. When a seemingly healthy grass lawn starts to develop problems, it can be hard to determine the cause. Lawn health can be compromised by over or under-watering, misuse of fertilizer, lawn disease or a number of other issues. Grubs are one common cause of many grass yard problems. The immature versions of beetles like Japanese beetles and June bugs, grubs live underground and feed on grass roots, causing a lot of problems for a lawn.



If you're trying to determine how to care for a lawn with symptoms like the ones listed below, you may be dealing with grubs:

  • Spongy turf — Grubs feed on the grass roots, which can leave patches feeling "spongy" since the turf is not well anchored.
  • Dead patches — The peak of grub feeding happens in the fall, leaving irregularly shaped dead patches in grub-infested lawns.
  • Loose turf— Since the roots are eaten away, the grass can be rolled up like a rug. If you are able to roll up a dead or spongy patch easily, check for grubs while it's up.
  • Animals digging up the lawn — Grubs make good food for birds, moles and other small creatures. Animals tearing up lawns may find grubs but it's also possible that they are only looking for worms.

To confirm that there is a grub problem, you'll need to dig up a few square foot sections from different parts of the grass yard. The grubs usually can be found if you dig these patches up to four inches deep, but when winter sets in the grubs will bury themselves deeper, so it's best to check before winter. More than five to ten grubs per square foot (depending on lawn health) can be considered a grub problem.


If you are finding ten or more grubs per square foot of grass, it is probably worth treating. There are a few options to choose from, both natural and chemical, depending on you or your client's preference:

  • Insect parasite nematodes — You can wage biological warfare on white grub species by purchasing certain nematodes. They are natural and safe but can be a little tricky since they can easily succumb to pesticides or improper handling.
  • Bacterial milky disease — If you're dealing with Japanese beetle grubs, you can treat with bacterial milky disease. It is also natural but can take a few years to overcome the grubs.
  • Pesticides — These can be applied in late summer, and sometimes targeted to patches where you see damage. It is important to water pesticides, both because they are potentially harmful to people and pets and because it allows pesticides to seep down to the grubs.

Being able to identify a grub problem and knowing how to care for a lawn with grubs can be a valuable tool for lawn care. Remember, healthier lawns can sustain more grubs without damage, so proper irrigation and mowing can go a long way to preventing grub damage. Find a Wright Dealer near you for the equipment and support to help you maintain strong, healthy lawns against any pest.

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