The Q&A Archives: Japenese Beetles

Question: I have 4 Knock Out Roses that are being attacked and eaten by Japenese Beetles. I have some Ultra-Fine year-round Pesticidal Oil on hand. Can I use that and how should I mix it? I have lost the directions that came with the bottle. Thanks! Loren

Answer: The Japanese beetles are awful pests, especially on roses, sadly the rose is one of their favorite plants. Some gardeners have success using a spray containing neem as a repellent. (Rose Defense is a good product.) Otherwise you can handpick them early or late in the day when they are less active, and certainly avoid using the pheromone traps which attract more than usual to the vicinity. You can also try treating them at the grub stage with milky spore or beneficial nematodes. Your local county extension may have additional control suggestions. I don't know if Ultra Fine Oil is safe to use on roses. The leaves are tender and could be burned with the product. I'd use Rose Defense instead, and follow label directions. Good luck with your roses.

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