Fungal diseases spread readily by spores, which can be carried by wind, water, and other organisms. The best way of handling fungal problems is usually through prevention (removing and/or destroying diseased plant litter, refraining from overwatering, and providing for good air circulation around plants). Fungicides are often used as prevention; once fungal disease has set in, it is very difficult --if not impossible-- to eradicate. Common fungicides used by organic gardeners include horticultural oils, baking soda dilutions, microbial solutions, and sulfur. Some homemade concoctions include milk, garlic, and horsetail brews.