Buds may rot. The fungus may also infect stems, causing a tan to brown canker to develop on the stem, or they may die back from pruning wounds. Cankers can weaken the stem. They may cause the plant to wilt, perhaps die, and to fall over. On some plants, the crown can become rotted.
Cuttings can rot from the base.
On all infected plant parts, in high humidity the fungus will produce characteristic spores . All affected areas become covered with a fuzzy gray fungal growth. Under magnification, the millions of spores are seen to be formed in clusters that resemble bunches of grapes. This fungus also causes damping-off of seedlings. E. Marrotte photo Gray mold spores on geranium.