Gray mold begins in cool weather but, unlike many diseases, it doesn't need high humidity to flourish. Low soil pH encourages more severe gray mold infection. The most characteristic sign of gray mold is its fuzzy, feltlike appearance.
If gray mold has been a problem in past years, begin spraying a copper soap at time of transplanting. Once gray mold is established, it spreads through plant tissue, so controls are of marginal effect. We recommend Soap-Shield Flowable Liquid Copper Fungicide. Use our Accugrow™ Soil Test Kit, or check with your county agent to find where to have your soil pH tested; if it is low, add lime to raise pH.