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
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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
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I volunteer at a large public rose garden in Longmont Colorado. Japanese beetles are destroying the blossoms after the first peak bloom in May/June. City staff will not treat the grubs, they say it is too expensive and hard to do on the scale of a large park with lots of well watered sod. They are talking about digging up a good portion of the memorial rose beds and replacing them with other perennials
Volunteers do the soapy water removal, but that is a not effective as control on the scale of the invasion Help!
I understand the challenge due to the cost associated with control in a large public garden. It would be great if there are some in our community of rose friends who have knowledge of what public gardens are doing these days. I will also check with Boerner Botanical Garden which is in my area.
If you can have one of your volunteers who are willing to spray the roses, you can use Azadirachtin. (This is the active ingredient in Neem oil, please note most Neem oil products do not have Azadirachtin available.). It won’t kill them directly, but will act as a repellent. A product such as Azatin XL, or ARBORjet’s AzaSol. AzaSol is not oil based so it won’t burn your rose leaves. Go to the ARBORjet website for more information.
I was recently told that Bacillus Thuringiensus in spray form can help control Japanese beetles. Does anyone have experience with this?
I thought that was only for catipillars?
There is a special Bacillus Thuringiensis var Galleriae is advertised as controlling the beetles, but it is not cheap. Product name is beetleGONE! I have not tried it yet, but does look interesting.
There are two products with a specific strain that controls Japanese Beetles and some other beetles. This includes BeetleJus. It contains the subspecies galleriae strain SDS-502, 76.5%. It is about $40 per 8 ounces.
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