The Q&A Archives: Moldy Soil when Starting Seeds

Question: 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 seeding, but sometimes the seeds don't germinate at all. How do I prevent this growth?

Answer: 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.

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