If you have not seen your first Japanese beetle this year, you probably will soon. The grubs are maturing in the rich soil under your lawn or the nearby field or golf course. The beetles will emerge and go straight to your roses to satisfy their ravenous appetites. We encourage a three pronged attack.
1. Remove the color – the best way to keep the Japanese beetles from eating you blooms is to cut them and take them inside. They are attracted to the color and scent in your rose garden. As soon as the buds begin to open and show color, cut them, put them in a Witherspoon Rose Caddy, and take them inside so you can enjoy them and the beetles can’t.
2. Spray, dust, or pick – there are many products on the market that are effective for beetle control. Sevin spray and Sevin dust work to eliminate beetles that visit your garden. Keep in mind that since Sevin is a broad-spectrum insecticide it will eliminate any other insect that visits your garden as well. For a more targeted approach, Bayer Rose and Flower Insect Killer and several products that contain pyrethrums may be used. Keep in mind that beetles have to eat the plant material for any spray to be effective, so they will do some damage before they die. Finally, picking the beetles off of your roses and dropping them into a jar of water is a time-tested and environmentally-approved approach that will certainly eliminate some of your beetle issues.
3. Get them early – apply Milky Spore to your lawn to reduce your local population of Japanese beetles over a couple of years. Milky Spore contains spores of Bacillus papillae which sterilize the grubs living in your lawn. When mature, these beetles will still munch and other beetles can still fly in from other areas, but this offers a long term solution to the overpopulation of Japanese beetles.
We do not recommend using Japanese beetle traps. Many times they draw more beetles to your yard than your roses will, and the beetles do not all go into the trap. The best place to put a beetle trap is in your distant neighbor’s yard. (You may want to check with them first.)
Controlling Japanese beetle damage in your rose garden is tough. A combination of approaches gives you the best chance of victory over the shiny little enemy. Stay diligent in your control measures and you can make it through “beetle season” without losing your roses, or your mind.