Paeonia Wilt - Botrytis paeoniae only affects paeonies.
It is a fungal disease that infects the leaves and stems of the plants.
The foliage becomes discoloured and eventually collapses, and the flowers may die before opening.
The infection can be recognised by a grey fuzzy mould that forms just behind the flower bud and/or when sections of stem shrivel and turn brown.
If the attack occurs low down on the plant, the whole stem generally collapses.
This disease appears in spring or early summer just as the plant has budded and is ready to flower, and is more common in wet seasons.
The only cure is to cut out and destroy all affected parts, even if this means cutting below ground to ensure no affected growth remains.
Be careful when removing and disposing of the diseased parts, if only to prevent the possibility of infective spores being blown about in the wind to other areas.
It is not known how long the disease can remain alive in the soil, so avoid replanting peonies on sites where the disease has previously occurred.
No chemical controls are available to home gardeners.