I'm not normally a violent person. And working in my garden usually helps me achieve an even more Zen-like state. But three summers ago when I discovered Japanese beetles feasting on my Frau Dagmar Hafstrup roses, I became an unrepentant murderer.
The Beetles—not music to my ears!
Japanese beetles have been spreading from the Eastern U.S. to the South and parts of the Midwest for the last 30 years. In Minnesota, where I garden, their populations have skyrocketed in the past decade thanks to perfect weather conditions, increased plantings of susceptible plants species and new housing developments with inviting soil.
Voracious and hardy
Adult Japanese beetles chow down in groups, consuming both the flowers and foliage of their favorite plants for about six weeks each summer. Their feeding frenzies can have devastating results. After mating, female beetles lay their eggs in the soil, and the grubs feed on grass roots in the fall and spring, seriously damaging lawns, nurseries and golf courses.
Waging war (unsuccessfully)
As an organic gardener, chemicals are not part of my arsenal (and frankly, they have a spotty record when it comes to defeating this pest). Instead, I spent the last two depressing summers knocking hordes of beetles off my roses into a bucket of soapy water three or four times a day. I managed to keep my roses alive, but murdering beetles does not make for a Zen-like gardening experience. And when the Japanese beetles devoured my 18-year-old North Star Cherry tree last summer, I knew I needed a different approach.
Don't plant their favorite foods
According to the U.S. Department of Agriculture, these are the top 10 favorite landscape trees and shrubs for Japanese beetles:
The 60-ft. American Linden and two 20-year-old crabapples in my front yard are at the top of the "most susceptible" list (my now dead cherry tree was too). I'm not ready to chop down my remaining trees, but last fall, I decided to change my beetle-fighting strategy.
My radical solution—no more free lunch
I decided to get rid of all the plants in my yard that Japanese beetles love (even though I love those plants too). So I dug up all my beloved roses except the one the beetles had left alone. And I also chopped down my gorgeous grape vine, another beetle favorite. In their place, I planted Japanese beetle-resistant shrubs, vines and plants, including conifers, honeysuckle and ornamental grasses. Rose lovers will understand how radical this is, but it'll be worth it if my garden becomes a beetle-free zone again.
A good friend called me a few days ago—this season's Japanese beetles had arrived in her garden that very morning. I've been checking mine each day and so far, no beetles. I've got my fingers crossed (and my bucket ready!).
Your local extension service is the best source for which plants in your area are likely to be susceptible and resistant to Japanese beetles. For more information on Japanese beetle control measures.
For more information about how to combat pests indoor and out, check out these great articles:
Do Your Own Pest Control
Fall Pest Prevention Tips
I had to fight the Japanese Beetles for years and my roses and garden is still intact in north Georgia area. There have been several things I do before the major attack happens and when the assault is on. When I spot the first Japanese Beetles I spray the most attacked plants with dissolved laundry powdered soap solution with my back pack sprayer as the initial deterrent technique. I try to eliminate using any insecticide at this time on the roses and plants to help keep the helpful bugs and bee population high. There is a greater chance of Japanese beetle infestation at times when the wind is blowing or if a neighbor has set-up one of those Japanese Beetle traps nearby.
The item that works best is to get a 1 to 3 gallon plastic bucket fill it up with 2 inches of water, add insecticide in the water or keep it out and add some laundry soap in the water to be environmentally friendly. I walk around my plant beds and spot the locations of beetles on the plants. I bring the bucket close to but below where the beetles are and swing and shake the flower, branch or leaves on the inside of the plastic bucket. The Japanese beetles will attempt to fly away but they usually do not fly upward but rather down and to the side to try to escape. In doing that they will bump on the inside of the plastic bucket and fall into the waiting water below. I have well over a 95% capture rate of Japanese beetles this way. The captured Japanese beetles will drown the other beetles in the water to try to escape., The water and the insecticide or soap solution in the water should kill them. I have to remove leaves and twigs out of the water in the bucket so they cannot get dry and try to fly out. I often get more than 30 Japanese Beetles captured in the bucket in a short time span. If there are a lot more present and the bucket is getting full I would decant the water and Japanese beetles on the driveway and squash them and repeat the process. You do need water in the bucket to keep them wet from flying out. I have killed hundreds of Japanese beetles during the time of infestation.
I normally do significant Japanese beetle monitoring for a week to two weeks after the first infestation is spotted. Afterwards the Japanese numbers are normally low and limited monitoring is required after that point.
This bucket technique is safe an and it saved my trees, roses and plants over the past 19 years in the north Georgia area. I may have some scared plant leaves but the Japanese beetle population gets eradicated in my yard in a short time span and it is environmentally friendly to other beneficial insects.
Regards, Richard Urbantas
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