Japanese Beetles love to eat my roses. In return, I do not love them. After living in California for a decade, I had forgotten this enemy of the garden. After moving back to Connecticut and getting reacquainted with our imported pest, I realized I needed an organic method to rid my yard of Japanese Beetles and save my plants. After asking around, I learned about several methods.
I called up my mum first to ask advice. Her method for capturing Japanese Beetles had always been a singular one. Using a canning jar with a lid, she slides the beetles in and closes the cap quickly and leaves the beetles there until they die. If you just have a few beetles and time, this method works well.
Since I am not as patient as my mum, I asked what her mum used to do about bugs. She threw soapy dishwater on them. This didn’t suffice, since I would need more dishwater than a large restaurant.
Some gardeners suggested a Japanese Beetle trap from a store, but others told me that traps actually entice the beetles from the neighbor's yard to come on over for the party in your garden.
My preferred remedy combines the jar and dish soap methods together.
I use a shallow square or round baking pan filled an inch with soapy water. Anything deeper, with more water, becomes too heavy. A wide pan maximizes the surface area and catches more bugs. I hold it one hand and shake a branch of my plant over it. Sure enough, all the Japanese beetles on that branch drop nicely into my trap.
Beetles can’t swim. The soap bubbles soften their landing so that they don’t belly flop and bounce right back out. Once in the water, it is all over. They drown and are also poisoned by the soap.
Every morning during July and August, I go out to my garden with my pan of soapy water and a cup of coffee. Early in the day, the bugs are still sleepy and are more likely to drop off the branch rather than fly away.
Give the beetles a couple hours to meet their maker. If you are mischievous like me, you can fool your kids into thinking you are making beetle juice to drink with dinner.
These methods leave the bees, spiders and lady bugs alive to do their jobs.
Japanese Beetles start life as grubs in your lawn. Organic products to eliminate grubs will result in fewer flower-devouring adults. The more adults you catch in the summer, the fewer babies they will make for next year.