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Japanese Beetle Larvae Infestation #947992

Asked November 01, 2026, 5:07 PM EST

Hello, We have been living at our home for 4 years now and have been dealing with Japanese Beetle larvae since owning the home. It started off in a small section of our front yard, and as of now, our front yard is mostly dirt and the back yard is 50% dirt. We can pick up giant sections of grass up with ease and find dozens of larvae underneath. We identified the issue 3 years ago and tried to use non toxic methods to address the larvae. For those 3 years, we've applied Milky Spore to our yard with minimal effects. We also attempted nematodes this fall, but were unable to properly tend the nematodes due to some medical needs. The pictures attached represent our yard today and we are looking for help. What can we use to treat our yard that is effective against these larvae? We are open to chemical interventions now. We have also read that high fescue grasses are resistant to these larvae. Can you provide any information as to why they are better and what brands you would recommend that are easily purchasable at a Menards/Home Depot? Our plan for the rest of the year is to clear out as much of the dead grass as possible and place seed on the entire yard just before the first snowfall with the hopes that the seed can grow right away in the spring, utilizing the snow melt to help jump start its growth. We are open to hearing other means or methods to help restart our yard and make it look better again. thank you

Hennepin County Minnesota

Expert Response

Thank you for writing.
That is unusually heavy and long. 
A couple thoughts. I do not know if you are using Japanese beetle traps but if so, STOP!  They use a sex hormone to draw beetles into the trap that draws beetles from a long distance away. Check with your neighbors. 
The beetles can be suppressed with different lawn care practices.  
Your lawn should be allowed to grow to 4-4.5 inches and cut to three. Taller grass means deeper roots and that makes it harder for the beetle to split the sod as they are doing.
Allow the clippings to sit on the grass to increase organic matter in the turf. 
3/4 inch water twice a week. 
Two seasonal applications of a 10-0-5 NPK sustained release fertilizer. 
No weed or pre-emergent crabgrass herbicide-- they weaken grasss. 
Your lot is on the shady side.  Avoid rye and bluegrass pick grass seed that is 80-85% fescues from a garden store not a hardware store. If the lawn is really compacted consider core aeration this fall. Its not too late for dormant season seeding. If you do not, then seed in early April. If you do do dormant seeding water until about Dec 10.  DO NOT MOW this year. 

https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/dormant-seeding

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