Japanese Beetle Solutions
Do you have Japanese beetles in your garden? I’ve had them for many years now, and I’ve tried several solutions for dealing with them. I’m happy to report that I’ve found a solution that helps. “Helps” is the key word. This method doesn’t eliminate them, but it definitely reduces the number.
Before we discuss what’s worked, what have you tried?
Popular (Yet Controversial) Methods for Japanese Beetle Control
- I’ve never used beetle traps because most sources say they actually attract more beetles. Apparently, the traps (treated with flower scents and pheromones) and the dying beetles (also releasing pheromones) draw more beetles in.
- I don’t use insecticides in my garden, so that option was off the table. Plus, they have to be regularly re-applied, and even the “organic” ones are harmful to other insects and pollinators. (With that said, I do use organic neem oil on indoor plants.)
- Diatomaceous earth is another method-but it, too, can be harmful to monarch caterpillars and other garden critters. So, again, not an option I was willing to consider.
- Applying nematodes is another method some gardeners recommend but one I haven’t tried. Several issues here: they have to be applied at certain times of day and certain times of year, they must be a specific species to be effective at eliminating Japanese beetles and the soil and soil moisture must be optimal for them to work.
Organic Methods for Japanese Beetle Control
- Soapy Water – With this method you can simply pick the beetles off the plants and drop them in the bath, or shake them off the plants into the water. Mix a couple tablespoons of dish soap with water in a small (approx. two cups) container. Empty beer or soda cans work well because the beetles have even less of a chance to escape. The soapy solution kills the beetles-they drop to the bottom and drown before they have a chance to release pheromones.
- Soapy Spray – You can mix the same ratio of dish soap with water in a spray bottle, and spray it on your vulnerable plants. The problem with this method is that you’re likely killing and repelling beneficial insects at the same time. So, while I’ve tried it, I don’t feel good about it.
- Stomping – If you only have a few Japanese beetles (other methods are working but the beetles aren’t eliminated), you can pick them off and quickly stomp them. This destroys them fast before they have a chance to release those pheromones.
- Companion Planting – Some plants, like garlic, scallions, marigolds and catnip, tend to repel Japanese beetles. Try interplanting these repellents among other plants in your garden to help keep beetle numbers lower.
- Milky Spore – This method works best for me. I’ve been using it for a few years now, and it seems to have significantly cut down on the number of Japanese beetles in my garden. The trick is that you need to place it in the garden in late summer or early fall (late August-September). The two main reasons? Ideal soil temperature for effectiveness is 60 to 70 degrees, and it only works on the grub stage of Japanese beetles, which are more active, close to the surface and prevalent late in the season.
Since milky spore is only effective against Japanese beetles, it won’t harm beneficial insects. It’s organic and extremely safe for use around children, pets and non-targeted species. It offers long-term, ongoing control, and only needs to be applied once per season. Follow the directions on the container for application, and then water the treated area to help the milky spore soak in and reach the grubs.
Don’t expect dramatic change after the first year of treatment; it can take up to three years to see a significant decline. I did notice a reduction after a couple of years, and even more each year since.
Here are two great sources for more information on eliminating Japanese beetles: HGTV and Growing a Greener World. Good luck!
Beth Stetenfeld is an organic gardener, native-plant enthusiast and garden blogger and writer. She’s also a master naturalist volunteer and instructor.
Danger! When I first used a Japanese Beetle trap, after two days it was filled with BEES. I took it back to the store, and told them I thought they should not sell the product. So I pick the beetles and drop in soapy water.
Thank you gir protecting our bees. ❤
Beetlejus works pretty well for me especially in big areas like trees and respberries
Japanese beetles have taken some of the joy out of gardening for us in Burnsville. We once had more than 50 roses, shrub and tea. For several years we just trimmed them all back for several weeks until the beetles declined in early August. But what’s the fun of having roses if you can’t have flowers. We also removed a large Linden tree in our front yard that would be be full of beetles and defoliated by summers end.
We have controlled by knocking them into soapy water, hundreds a day sometimes.
However, over the last couple years we have seen more and more beetles with the tell-tale white dots on their heads of eggs of the winsome fly. This year we are seeing significant numbers of these beetles with white specs on their heads.
This summer we have noticeably fewer beetles. Still too many. Cold winter? Parasites? Or just luck? I don’t know but I am hopeful we might be reaching a nuisance rather than pestilence phase.
Not a coincidence. Theyvhavr found that fly will kill the beetles and are now using it for beetle control. UW Minnesota just released info and you might want to look at it.
Sounds very promising.
Removing the Linden probably made a HUGE difference as that is one of the primary draws for JB. My street was lined with lindens and I am convinced that was the reason we were decimated in my neighborhood. Two of the lindens on the terrace I had removed due to disease and I had fewer beetles. 10 years ago I gave up on my rides, ripped them all out when I learned that like the lindens they were a JB favorite.
Theres hope! After being jp free, I’m planting Rose’s again.
Good luck!
I want to know where these disgusting little creatures came from because when I used to garden with my mom back in the 80 s and early 90 s the stupid ugly things were few and far between but in the early 2000s they were thick. Couldn’t even make a hot dish or a nice meal without the damn things flying directly into your food. It was horrifying. So where did the freaks come from? I heard once that the farmers had them shipped in to control the pests that munched on their crops. If that was true they should have found a way to get rid of the disgusting things after their harvest so the rest of us town folk didn’t have to put up with the bastards all the time because that’s what it is a year around complete infestation and while the farmers reap more and more benefits while the rest of us have to deal with the disgusting filthy stinky vermin. It’s time to find a better solution and let the farmers figure it out they’ve got plenty of time.
I pick beetles and drop them into soapy water as my main method of control. I have utilized the BTg product called BeetleJus from Gardens Alive on my raspberries when the infestation is very heavy. I also use drip irrigation in my raspberries so it minimizes the area of soft soil in which the beetle can lay eggs.
I catch them one by one. First year I got 500 and drown them in soapy water. Next year I have 380-ish…this year because of dry season (?), I caught only 10.
If you don’t want to touch the beetles, here’s a solution: buy one of those kids’ pail and shovel sets, and use the shovel to whack the beetles into the pail filled with soapy water. I’ve been doing this for 4 years and it works. They’re slower than you might think.
I am going to try the soapy water spray tomarrow. I been feeding the birds n now I have more birds than before so they will have a feast on these destructive bugs.
Has anyone tried neem oil? I started spraying my gardens and fruit trees early spring to kill eggs, they just started showing but not as many as last year, I keep spraying once per week to control them but seems like it’s a no win situation they never go away completely
It is sad after so much work to see these beetles destroy everything so fast
Best wishes everyone
They are notorious little pests that will eat everything. I have been proactive and constantly at war. When I can I patrol my yard with a fly swatter and have a ton of brush growing along the back fence they are attracted to so I smack them against the leaves especially when there is large clusters and many go down. I hang Spectracide Japanese beetle traps closer to the house and have found the spray is also helpful but only apply in the evening when sun is low as not to burn the plants. It doesn’t seem to last as long as they claim or hurt the plants. I have found that these efforts are keeping my roses, sunflowers and Japanese cherry trees from being devoured but they are still trying. I pick them off and stomp them. Its a struggle and I have eliminated quite a few they just keep on showing up.
Do not hand the traps in your yard to catch or trap Japanese Beetles!!! They have something to attract the Beatles and you will have many many more than you started with.
I’ve used milky spore for 3 years now and I’ve seen a HUGE reduction in Japanese Beetles. I typically would see grubs every time I planted something. This year I’ve planted dozens of bulbs and have only seen a few grubs. We take a 3 pronged approach to these bastards. 1- Milky Spore – it takes a while but by the second year you will see improvement. 2- Beetle bags- lots of them on the edge of our property down wind, before you get to our plants. 3- search and destroy- early in the am or at dusk the beetles are much slower. Take a bucket of soapy water and whack them off your plants into the bucket. This works. All 3 methods have saved my plants. I hate these little guys with a passion.
What’s the difference in using milky spores vs nematodes? I have used Nematodes 3 times now. I’ll let you know if it’s working after Aug.
Well, we tried marigolds and they are full of beetles…going to rip them out. These are planters I have on our deck railings. I thought I might give marigolds a try this year, but it didn’t work out. ? it an infestation I can’t beat!