|I salvaged about 3 dozen tuberous begonias last fall. They have been growing in my basement under lights without a lot of trouble. All of a sudden around Christmas, grey mold appeared. I isolated the bad ones, sprayed a fungicide. I've even put down a fan. What can I do before they are all covered with the mold? I'm picking off the infected leaves now because the majority of the begonias are involved.|
|You are off to a good start! Grey mold likes dark,humid, cool areas with low air circulation. The fan was a very good idea, as is picking off the leaves. Try to prevent it from sticking around by continuing use of the fan (without placing the plant in a drafty area), reducing watering, cease misting and, if possible, moving them to a warmer spot. Was the fungicide at all effective? If you feel that it was, continue applications being careful to follow label directions.
Actually, tuberous begonias prefer a little down time in the winter. Ideally, you should lift the tubers out of the soil after the tops begin to yellow, allow them to dry for a few days, and then store them in dry peat moss for the winter. You can get them off to an early start in pots of moistened medium in a warm spot (bottom heat is best). I'm not sure how yours will perform when transplanted to the garden in spring, but I advise storing dormant tubers next winter.