What are you doing to combat Japanese Beetles?

What are you doing for Japanese beetles this year?

Each year I track when I see the first Japanese beetle in my garden. That tends to be the last week of June to about July 3rd. 2-3 weeks prior to the time frame, I lay down a product to combat grubs in my rose garden and around other plants that they seem to like. When they do appear, I pick them off and drop them in a bucket of soapy water, which kills them.

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Tracking the first appearance of Japanese beetles in your garden each year is a proactive approach to managing these pests. Typically, you observe them from the last week of June to around July 3rd. To combat their larvae, you apply a grub control product 2-3 weeks before this period, targeting the time when grubs are most vulnerable and preventing them from maturing into beetles. When adult beetles do appear, you manually remove them and drop them into a bucket of soapy water, an effective and environmentally friendly method to kill them. This combination of preventive and immediate action helps keep your rose garden and other favored plants protected from damage.


We use Beneficial nematodes on the lawn. At one point we had so many Japanese Beetles that they defoliated a mature cherry tree. Using the nematodes took care of the problem. We purchased them on Amazon

I don’t have JB but I have 2 other varieties. Sugar Cane beetles or May beetles and Chafer beetles or June bugs (as we kids called them).
This is the first year I’ve ever seen Sugar Cane beetles. They came in late March and started eating the leaves and blooms. Our beetles come out at night. These were the blooms I would be exhibiting at our spring show here in South Louisiana. Needless to say I had a lot of roses I couldn’t use. There was not much I could do and it was stressful. They finally stopped eating and a couple of weeks later the June bugs started eating my roses. There were so many that I couldn’t pick them off like I did with the sugar cane beetles. No one told me to try nematodes or treat my lawn to kill the grubs during the last few years. Thanks John & Diane, I now have a plan and am looking forward to NO beetles!!

Knocking them into a jar of soapy water on my rounds a couple times a day (my beetle swimming pool!). Waiting out the time until they’re gone. I vigorously advise people against using insecticides that kill the beneficials or traps that lure beetle ps from all over the neighborhood.

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Hi John - Welcome! How long did it take for the nematodes to make an impact? Are there temperature restrictions - will they overwinter in colder climates? Thanks much

Ours start out slowly around May 30 or the first of June always giving us the naive impression that it will be a light year (stupidly, we always have hope). After a few weeks they laugh and come with their out-of-town relatives. We pick them off and put them in soapy water while we laugh maniacally as they drown. They are peaking at this time, and we hope will be gone in two weeks or so.

Great to hear from you, and you are doing an amazing job with the Society!

It improved each year and in 3 years we only had a handful of beetles. We applied for them twice a year in April and October. Not sure if they overwintered in our cold climate (Buffalo, NY).

See you at the National…John and Bonnie

We use cyonara usually once a week just to blooms - works pretty well