Cut plants to the ground after the foliage turns brown in the fall. Burn dead material. Select varieties that are resistant to botrytis blight. Phytophthora Blight Phytophthora blight is less common than botrytis blight, but it causes more damage to individual plants. Infection spreads down the stem from the buds.
Stems dry up and turn dark brown and leathery.
Plants rot at the ground line, or crown, of the plant. ControlQRemove diseased parts as soon as you notice them and pull out and burn badly infected plants. Cut plants back to the ground in the fall. Burn dead material. Wilt is caused by a fungus that lives in water-conducting tubes of stems.