Japanese Beetle Destruction

Q: Kelly, do you have any thoughts on dealing with Japanese beetles that are destroying my flower garden?

A: After observing Japanese beetles in my home garden for three seasons I’ve noticed the infestation and flower damage occurs primarily in late June through July. Try concentrating your garden with flowers that bloom in spring, late summer, and fall. Summer flowering plants such as roses, hollyhocks, Polygonum, and Hibiscus can be cut back just before flowering then allowed to rebloom after the infestation dissipates. Specific microbial and nematode products can kill Japanese beetle larvae in the soil, but I think there’s a consensus that they aren’t terribly effective in reducing adult beetle damage; the adults just fly in from nearby areas. Japanese beetle hormone traps will kill large numbers of adults but also attract more adults to the area. My conclusion at this point: avoid planting highly susceptible plants like Virginia creeper, grape, etc., and cut back susceptible flowers that blossom during July.

Written by Kelly Grummons, who writes our Q & A column, is co-owner of the mail order nursery businesses, coldhardycactus.com and dogtuffgrass.com