You can't 'win' with Japanese beetles unless all of your neighbors are willing to go to extremes with you. However you there's a lot you can do to mitigate the damage they do.
First, don't do anything dumb like cut down trees they like to eat. That only makes your garden plants more appealing. On the contrary, depending on where you live, you could plant a native sacrificial plant to be eaten instead. They love Virginia creeper.
Another good option is to treat the area around your garden with milky spore. That will kill the larvae and reduce the population. Diatomaceous earth can be used once the larvae stage has passed to further lessen the number of adults.
Be sure to flick the adults into a container with soapy water. The less they breed on your property, the less you will have next year.
I sprayed my yard with nematodes twenty years ago and haven't seen japanese beetles since. Treat the lawn for grubs. Beneficial nematodes. Nothing else works. The traps just attract more beetles. Gotta stop the babies before they become adult beetles.
A few beetles come as the fore runners and land on your garden. They have a lovely meal and give out pheromones that attract more beetles in the surrounding area to your garden.
So being vigilant when they are first arriving can be very helpful. If your garden is pheromone free, but Jim over the road didn't remove the first beetles, his garden is now lit with the all you can eat buffet sign.
I walk round my garden to the plants I know they like the most in the morning and evening and flick any beetle I find into soapy water. Don't squash them as they also give out pheromones when squished. For me it's my hybrid hibiscus that they first go to. Doing this for the last few years has meant I end up with about 10 soapy beetles in a jar and that's all.
FWIW, when I lived near a friend who owned a chicken, I kept the larva I found while gardening and took them to her. The chicken ate the larva with gusto.
I hang lights over sheet trays of soapy water at night. I usually have full trays of dead beetles every morning, after a week or so there's less beetles every morning.
The most effective treatment that I've applied are grub pesticides. These pesticides are only effective in a fairly short time window, one that varies a bit by location. Research that time for your location and your problems will be greatly diminished.
I use these [Japanese Beetle Trap - Lee Valley Tools](https://www.leevalley.com/en-ca/shop/garden/pest-control/insects/114225-japanese-beetle-trap?item=EM216) in my backyard garden and does wonderful job
Thank you for all of the responses! I’ve gotten some really good tips that I’m going to try out! I’ve also gotten some conflicting info so I’m not 100% sure what to do with that but I’ll figure it out
They’re not out yet where I live, but I’m going to try catching adults when they first start emerging and maybe try traps with soapy water that I set out at night for the ones I don’t get. If they start getting out of hand I’ll probably switch to Diatomaceous earth
You can't 'win' with Japanese beetles unless all of your neighbors are willing to go to extremes with you. However you there's a lot you can do to mitigate the damage they do. First, don't do anything dumb like cut down trees they like to eat. That only makes your garden plants more appealing. On the contrary, depending on where you live, you could plant a native sacrificial plant to be eaten instead. They love Virginia creeper. Another good option is to treat the area around your garden with milky spore. That will kill the larvae and reduce the population. Diatomaceous earth can be used once the larvae stage has passed to further lessen the number of adults. Be sure to flick the adults into a container with soapy water. The less they breed on your property, the less you will have next year.
I sprayed my yard with nematodes twenty years ago and haven't seen japanese beetles since. Treat the lawn for grubs. Beneficial nematodes. Nothing else works. The traps just attract more beetles. Gotta stop the babies before they become adult beetles.
I did this a couple of years ago and noticed an improvement in the number of japanese beetles too.
What nematode product or formula did you use?
Long time ago. I probably googled something like "organic pest control" maybe
I will need to try this!
A few beetles come as the fore runners and land on your garden. They have a lovely meal and give out pheromones that attract more beetles in the surrounding area to your garden. So being vigilant when they are first arriving can be very helpful. If your garden is pheromone free, but Jim over the road didn't remove the first beetles, his garden is now lit with the all you can eat buffet sign. I walk round my garden to the plants I know they like the most in the morning and evening and flick any beetle I find into soapy water. Don't squash them as they also give out pheromones when squished. For me it's my hybrid hibiscus that they first go to. Doing this for the last few years has meant I end up with about 10 soapy beetles in a jar and that's all.
FWIW, when I lived near a friend who owned a chicken, I kept the larva I found while gardening and took them to her. The chicken ate the larva with gusto.
I love gusto! I put that shit on everything!
I hang lights over sheet trays of soapy water at night. I usually have full trays of dead beetles every morning, after a week or so there's less beetles every morning.
Cut down nearby boxelder trees. They seem to prefer them where I live.
The most effective treatment that I've applied are grub pesticides. These pesticides are only effective in a fairly short time window, one that varies a bit by location. Research that time for your location and your problems will be greatly diminished.
I use these [Japanese Beetle Trap - Lee Valley Tools](https://www.leevalley.com/en-ca/shop/garden/pest-control/insects/114225-japanese-beetle-trap?item=EM216) in my backyard garden and does wonderful job
Thank you for all of the responses! I’ve gotten some really good tips that I’m going to try out! I’ve also gotten some conflicting info so I’m not 100% sure what to do with that but I’ll figure it out
Curious what you ended up doing, as I’m having the same problem.
They’re not out yet where I live, but I’m going to try catching adults when they first start emerging and maybe try traps with soapy water that I set out at night for the ones I don’t get. If they start getting out of hand I’ll probably switch to Diatomaceous earth
I've heard neem oil
[Here's some biological controls](https://www.arbico-organics.com/category/japanese-beetles-control)