April 10, 2012 | By Mr Grass,
Updated June 24, 2019
According to a University of New Hampshire publication on milky spore disease, there are more reasons NOT to use this product than to use it in your home lawn. Milky spore has been around for decades and was the first biological disease to control Japanese beetle grubs. Milky spore comes in a powder and consists of a bacteria.
The first reason not to use milky spore is that it was manufactured to control ONLY Japanese beetle grubs. Unfortunately there are many more turf damaging grubs in NH and VT including Asiatic beetles, European and masked chafers, June and May beetles and armyworms. So now you understand that even if milky spore could work, you would only be controlling one grub out of many…not good odds.
Secondly, you must have sufficient numbers of Japanese beetle grubs in your lawn to promote the bacterial population enough to expand and spread out in the soil. Therefore, if you do not have a large Japanese beetle grub population, one where you would likely see damage – why bother?
The third reason not to use milky spore in NH and VT is the fact that the soil temperature must be 60-70 for three months. This consistently high soil temperature rarely occurs in our region. Additionally, the bacteria can take over 4-5 years to build up…under ideal conditions…with a high population of Japanese beetles grubs! Wow!
To summarize, even under ideal conditions, using milky spore disease to control grubs, even Japanese beetle grubs, is a serious waste of money and time. It’s best to consult with a lawn care professional because without knowing insect or disease life cycles, product components, mode of action, and application method – you could be applying the wrong product, at the wrong time, for the wrong pest.