Grubs in lawn - Ask Extension
What do you recommend for controlling grubs in the lawn. I discovered a high concentration of what I assume are Japanese Beetle grubs, but I’m awar...
Knowledgebase
Grubs in lawn #851245
Asked September 25, 2023, 11:06 PM EDT
What do you recommend for controlling grubs in the lawn. I discovered a high concentration of what I assume are Japanese Beetle grubs, but I’m aware there are other grubs that look similar.
I was about to order milky spore, but I want to be sure I have JB.
I’m trying to do things organically so as not to kill everything. Another thought is nematodes.
Kent County Michigan
Expert Response
You've established there is a grub problem. Now we need to determine which grub it is by looking a the anal slit and raster pattern of hairs on the 'behind' of the grub. Open the first 3 links for id instructions:
Grub ID-Cornell
Identifying White Grubs-MSU
Id of White Grubs in turfgrass-OSU
More info on organic control of grubs:
Japanese Beetles in Yards & Control-UMN - read organic controls section
Take Control of Lawn Grubs w-o chemicals-PSU
Natural White Grub Mgmt in Lawns-UMd
How to Choose & Apply Grub Control Products-MSU - not organically focused, but good info on when to treat
IPM of Turfgrass Insects-Purdue
Both milky spore and nematodes will work over time although results may vary. Bt is another option too.
Nematode application should be made fairly soon after receiving them but soil temps should be above 50 degrees F. See the following list of recommendations and links on nematode application:
store nematodes in refrigerator after receiving, until application
always thoroughly water lawn before & after nematode application 50F-80F soil temp (optimum 60F-70F)
never apply in full sunlight, best on a cloudy day or at dawn or dusk
stir / agitate solution while applying to keep nematodes from settling, multiple applications may be needed
https://extension.psu.edu/insect-parasitic-nematodes-for-the-management-of-soil-dwelling-insects recommendations on application
https://extension.umd.edu/resource/white-grub-management-lawns
https://extension.unh.edu/blog/2019/09/how-do-i-treat-grubs-my-lawn see nematode application recommendations
https://extension.entm.purdue.edu/publications/E-271/E-271.html
Grub ID-Cornell
Identifying White Grubs-MSU
Id of White Grubs in turfgrass-OSU
More info on organic control of grubs:
Japanese Beetles in Yards & Control-UMN - read organic controls section
Take Control of Lawn Grubs w-o chemicals-PSU
Natural White Grub Mgmt in Lawns-UMd
How to Choose & Apply Grub Control Products-MSU - not organically focused, but good info on when to treat
IPM of Turfgrass Insects-Purdue
Both milky spore and nematodes will work over time although results may vary. Bt is another option too.
Nematode application should be made fairly soon after receiving them but soil temps should be above 50 degrees F. See the following list of recommendations and links on nematode application:
store nematodes in refrigerator after receiving, until application
always thoroughly water lawn before & after nematode application 50F-80F soil temp (optimum 60F-70F)
never apply in full sunlight, best on a cloudy day or at dawn or dusk
stir / agitate solution while applying to keep nematodes from settling, multiple applications may be needed
https://extension.psu.edu/insect-parasitic-nematodes-for-the-management-of-soil-dwelling-insects recommendations on application
https://extension.umd.edu/resource/white-grub-management-lawns
https://extension.unh.edu/blog/2019/09/how-do-i-treat-grubs-my-lawn see nematode application recommendations
https://extension.entm.purdue.edu/publications/E-271/E-271.html
Thanks for your response.
The butt slit looks crescent so s/b JB.
We had started to prep the lawn in order to overseed but don’t want to do this before the critters are dead so we’re looking for a quick solution now.
We think grubGONE! is a good choice for us.
If you have another safe, quick solution, please let me know.
Thanks again,
Karen
<personal data hidden>
I think time has expired for effective grub control this year. You should wait until spring to apply grubGONE. By now grubs have greatly reduced or stopped feeding and moved deeper in the soil to hibernate for the winter. More info here:
Control Lawn Grubs w/ IPM-PSU
How to Choose & Apply Grub Control Products-MSU - see timing recommendation for application
Natural Organic Lawn Care-OSU
Organic Turf: FAQ-UNH
It's also too late to overseed this year as there isn't enough time for the seed to germinate and become established before winter sets in. You might consider dormant seeding to get a head start in the spring. More info here:
Fall Dormant lawn seeding-UMN
Late Fall Lawn Seeding-Illinois
Dormant Lawn Seeding-K-State
Renovating A Lawn for Quality & sustainability-UMN
I would be remiss if I didn't also recommend doing a soil test, if one hasn't been done in 2 the past years. Knowing the type and fertility of your soil is the starting point to establishing & maintaining a strong turf that can resist diseases, weeds, moss and insects/grubs, look great and at an optimal cost. More info here: Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer Do this for next year's use.
Control Lawn Grubs w/ IPM-PSU
How to Choose & Apply Grub Control Products-MSU - see timing recommendation for application
Natural Organic Lawn Care-OSU
Organic Turf: FAQ-UNH
It's also too late to overseed this year as there isn't enough time for the seed to germinate and become established before winter sets in. You might consider dormant seeding to get a head start in the spring. More info here:
Fall Dormant lawn seeding-UMN
Late Fall Lawn Seeding-Illinois
Dormant Lawn Seeding-K-State
Renovating A Lawn for Quality & sustainability-UMN
I would be remiss if I didn't also recommend doing a soil test, if one hasn't been done in 2 the past years. Knowing the type and fertility of your soil is the starting point to establishing & maintaining a strong turf that can resist diseases, weeds, moss and insects/grubs, look great and at an optimal cost. More info here: Don't Guess-Soil Test-MSU and MSU Home Soil Test-self mailer Do this for next year's use.
