Prevent mold from growing in shoes by keeping footwear dry. Mold grows in damp environments and by leaving wet shoes in a dark, damp closet that can help spores multiply. Dry a wet shoe or insole outside in the sun or in a warm, lit room before closet storage. Your shoe storage environment should have a relative 40-50% humidity and constant ventilation. Not only can mold grow in the wet shoe, but mold can move to other dry shoes in the same area.

Closet lighting can help keep a closet warm and dry and prevent mold from multiplying. Keep your closet door shut as humidity from a bedroom or adjacent room can increase dampness in your closet. Shut closet doors to keep moist air from entering.

Remove dirty clothing and shoes from the closet. Molds, a form of fungi, feed on dirt and food particles. Finally, if possible, replace wood closet components and shelving with metal, that is a much more mold/moisture resistant than wood.