Botrytis blight, also known as gray mold, causes flowers, leaves, and buds to drop off too soon as well as cause bud rot, wilted shoots, and foliage. High humidity promotes the spread of this fungus, which results in masses of spores that range in color from brown to gray on the peony. Plants with the infection experience twig die-back, flower buds that do not open, and wilting and dropping of their leaves from the twigs. Infected plants won’t suffer significant harm if the fungus is kept at bay with proper maintenance and cultural control. In humid, damp weather, regularly check the peonies for fungal illnesses. Regularly remove any plant debris that has fallen to the ground beneath the peony and dispose of it properly. Immediately remove from the peony any plant tissue that is dead, sick, or infected. Early spring applications of copper sulfate will aid in botrytis blight defense for the peony. However, don’t use it on shoots that are shorter than 6 inches.
