Milky Spore is a naturally occurring microscopic bacteria (Bacillus popilliae) that kills Japanese beetle grubs before they can grow into ravenous adults. It's a long-term solution because it survives winter temperatures. The Milky Spore population increases each year, reaching peak effectiveness about three years after application, and lasts ten years or more.
"Everyone keeps asking me: what did I do to get such beautiful roses? And I have to say, it truly is the Milky Spore that has done the trick. If not for Gardener's Supply Company and Milky Spore, my garden would be infested with those shiny Japanese beetles from flowers to stems to roots."Maureen, Chicago IL