Grub Worms

Asked June 9, 2017, 6:28 AM EDT

I have a recurring grub worm problem. I thought I had solved it last year with a commercial eradication product but they are clearly present. If there is a non commercial solution that can be mixed and used I would be very interested in knowing about it. Thanks.

Baltimore Maryland

3 Responses

Grubs are a normal part of the lawn ecosystem. Usually the roots of grass grow faster than grubs can eat so grubs have little to no impact. And, having a few grubs around keeps the enemies of grubs around to eat and infect them.

The problems arise when they occur in large numbers--about 10-12 per square foot--and we have dry/droughty weather so grass root growth slows. The population can easily be counted using a shovel to look under the sod.
Unless you have large grub populations that are killing your sod (eating off the roots so that you can roll up the sod like a carpet), we do not recommend using any grub products. Not only does it waste your money, but these are toxic chemicals that affect the other organisms in your soil.

Most lawns never have a true grub problem. Irrigated lawns, however, are very attractive to beetles when laying their eggs--and thus have lots of grubs. There are several grub control products on the market, such as Grub-Ex, that are effective. We do not endorse any particular product. They must be applied at the correct time and manner to be effective.

Grubs in spring barely eat, and it is a waste to apply products early. Read directions on the product carefully.


Thanks for your response. However, I was just out pulling up the crabgrass that is growing in the areas that have been left bald. I have been planting clover as a replacement for the whole mess, but it comes in slowly allowing the crabgrass to take over. Any thoughts?

We do not know how you are managing your lawn and what type of grass you have.
If you wanted to keep clover, you cannot spot treat to kill other weeds as it would kill the clover. Also, It does not like the intense heat of summer and may go dormant during drought - in this regard it is similar to cool season turf grasses such as tall fescue. In extreme drought, large patches will likely die. Also, in the winter it goes dormant.

Turf type tall fescue is the recommended species for full sun to part shade. If you have shady areas, fine fescues are recommended.
It may be easiest to go with a tall fescue lawn. If you have large bare areas you could lay sod now. You would have to keep it watered until established and watered during dry periods this summer.
Otherwise, you could overseed or renovate in the fall to have a thick stand of turf.
Test your soil if not done in the last several years. Results give pH, liming, and fertilization recommendations. You may want to test for organic matter in the soil.

See our publications on lawn renovation and overseeding, fall fertilization, and our turfgrass maintenance calendar for more information on maintenance and care throughout the year.