Q. Whenever I start seeds indoors, a white mold grows on the soil surface--it looks like fluffy cotton. I haven't determined if it hurts the seedlings, but sometimes the seeds don't germinate at all. How do I prevent this growth?
A. The moldy growth is due to overly wet conditions and lack of adequate air circulation. To prevent it, use fresh seed starting mix and water your trays or pots of seedlings from the bottom, allowing the top of the soil to dry out before watering again. If you use a plastic dome over the seedling trays or pots, prop up the dome a half-inch or so to allow excess moisture to escape.
Q. I've been growing perennials and vegetable seeds indoors, by a sunny window. Although I have used a commercial growing medium, some of the pots are getting moldy on the top. How can I avoid it, and how can I stop the mold that is already there from growing?
A. Mold on the top of the soil indicates too much moisture and not enough air circulation around the plants. Try separating the plants so air can freely circulate, and watering after the top of the soil has barely dried out. You can take a blunt knife or a spoon and gently remove the mold from the soil, then improve the conditions so it won't grow again. If your seedlings are strong, they shouldn't be adversely affected. If the mold has started to grow on the stems or leaves of the plant, they may not pull through, and you may have to replant. Cross your fingers that you've caught the problem in time!
