Lawn Grubs: How to Identify, Get Rid of, and Prevent Them
It was an early October morning . . .
I was up early just after sunrise. I opened the back door to let the dog outside and was shocked at what I saw.
The grass was all torn up. Kind of like a "grass massacre" (see photo below). I shook my head and looked again wondering what happened overnight. My first guess was that a deer got into the yard and dug up the lawn. That's what it looked like. But it didn't make sense because the yard is entirely fenced in.
My next thought was some other kind of animal, yet why? I mean this mess was pretty bad.
Figuring Out What Dug Up My Grass
I took a rake and a big garbage can to start cleaning up. As soon as I pulled a patch of grass, I saw them!
AHHHHHHHHHHHHHH! GRUBS! White ugly, creepy, wormy-like lawn grubs!
But how could these little worms make such a mess?
Types of Beetle Larva that Damage Lawns
There are several types of beetle larva (called lawn grubs, grub worms or white grubs) that damage grass including larva from the
- June Beetle
- Japanese Beetle
- Green June Beetle
- Masked Schafer Beetle
- Black Turfgrass Ataenius Beetle
What are Lawn Grubs (often called White Grubs)?
A classic lawn grub or white grub is a whitish C-shaped larva of a beetle (such as June beetles) that are about ½ inch in length. The beetles typically lay their eggs during mid summer in sunny areas of the lawn. Their larva (lawn grubs) live in the soil eating on the roots of grass and other organic matter leaving it dry, brown and dead.
Eventually grubs turn into adult beetles and come out of the soil to mate and lay eggs which hatch into more grubs.
Was this the culprit?
Lawn Grubs Attract Unwelcome Wildlife
Not only do grubs damage the lawn, their presence also attracts unwelcome wildlife. These critters have no concept of “property lines” and can easily find their way into even a fenced in yard.
Animals such as raccoons, skunks, moles and other rodents will feed on lawn grubs. They will strip away your grass or dig tunnels underneath in search for one of their favorite delicacies.
Important note: Many of these animals including birds also dig your lawn to find earthworms. Always confirm that grubs are present before pursuing a lawn treatment.
Identifying Lawn Grubs
Late summer or early fall: Lawn grub damage is usually visible from late summer and peaking in the early fall. If you have irregular patches of grass that are brown and dry, check to see if a patch easily peels away from the soil. If a patch of grass lifts up like a carpet with no roots holding it down, you likely have an infestation of lawn grubs.
In the spring: As your lawn begins to green up, look for brown patches that never turn green. These dead patches of grass may be grub damage from the previous fall.
WAIT – Some Grubs are Okay
As you inspect your lawn to identify that grubs are present, it’s important to know that a healthy lawn can easily support some grubs without the need for any type of treatment.
To determine the extent of the infestation, dig and lift several sections of sod the size of one square foot by approximately three inches deep. Then follow the guidelines in the table below.
Number of Grubs within a Square Foot
What To Do
No need to treat
6-9 in a healthy lawn
If lawn is healthy, no need to treat
6-9 in a stressed lawn
A less healthy lawn may require treatment, especially if animals are digging up the grass
10 or more
It's likely that the lawn will continue to be further damaged and will require a treatment plan
When to Apply a Lawn Grub Treatment
Grubs are larger and no longer feeding in the spring, therefore they are less susceptible to treatment. In addition, spring rains can easily wash away a treatment.
Midsummer to early fall is the best time to treat lawn grubs because at this point, grubs are small, immature and closer to the surface.
I got rid of the dry patches and cut the grass before treatment.
Simple Grub Control Options
Birds: Do what you can to attract birds to your yard using bird feeders, bird baths and nesting homes. Birds eat bugs including grubs.
Beer: Another lawn control option that is said to work is to set a beer trap. Use an old plastic bowl approximately three inches deep by six inches in diameter. Dig a hold so the bowl fits to where the top lip of the container is at ground level. Pour beer in the bowl.
Types of Grub Treatment Products to Consider
Always read the instructions and follow them carefully when using any type of lawn treatment. There are difference applications with different ingredients recommended for killing lawn grubs and/or preventing them.
Curative Products: Curative products will kill existing grubs on contact.
Preventative Products: Preventative products will kill grubs that are present at the time as well as those that may hatch throughout the season.
- Dylox – fast acting and most effective in the fall.
- Merit and Mach-2 – used early in the season as a helpful prevention.
- Milky Spore – effective and environmentally safe. Used on active grubs and as a prevention.
- Neem Oil – a botanical pesticide that repels against beetles and lawn grubs.
- Nematodes – a soil-dwelling worm that releases bacteria into the soil which in turn, infects and kills lawn grubs.
This is the product that I used.
Reseeding After Lawn Grub Treatment
Dead lawn patches should be reseeded. For me, it’s currently too late in the season. So I’ve cleared out most of the patches, treated the lawn with Scotts GrubEx, will also soon spread Winterizer fertilizer and then reseed in the spring. And hopefully, my yard will remain grub free!
This is Sharyn’s Slant
Great video on ALL TYPES of insects that damage lawns.
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.