Description
This plant disease, also known as gray mold, blossom blight, and bud and flower blight, is caused by any of several closely related species of fungi (Botrytis species) that infect many vegetables, flowers, trees, and shrubs. The fungus usually begins to grow on plant debris or weak or inactive plant tissue, such as old leaves, flowers, and overripe fruit. After the fungus becomes established, it invades healthy, actively growing plant tissue. Botrytis causes spotting and decay of flowers and foliage, and of fruits and berries, both before and after harvest. In some plants, it causes cankers or rots stems, corms, and bulbs. Botrytis spores are present in most soils. The fungus thrives in cool, moist conditions.
Control
The key to avoiding problems is good sanitation. Remove and destroy dead leaves and flowers so the fungus will not have a chance to produce the thousands of spores necessary to mount an assault on healthy plants. Keep the foliage as dry as possible. Water the plants at the soil level, instead of overhead, and space them far enough apart so that air can circulate between plants. Fungicides can also be helpful. Spray with a fungicide containing chlorothalonil, captan, maneb, or mancozeb every 10 to 14 days as long as the mold is visible. Check to make sure that your plant is listed on the product label.
