Is It Safe to Compost Plants With Powdery Mildew?

A compost thermometer helps gardeners determine whether a pile reaches temperatures hot enough to process diseased plant material safely. Powdery mildew plants belong in a properly managed hot pile, while cool or unreliable piles call for another disposal method – Pexels

Powdery mildew can make a perfectly respectable garden plant look as though someone dusted it with flour. The good news: gardeners do not automatically need to ban every mildew-spotted leaf from the compost pile, but the answer depends heavily on how hot and active that pile gets.

A casual backyard heap that slowly decomposes presents a different situation from a well-managed hot compost pile. Knowing that distinction can keep a gardener from either wasting perfectly compostable plant material or accidentally giving plant disease a cozy little vacation in the garden.