It may be that you see it growing on walls or floors or perhaps you smell a musty odor. It's important to correctly identify mildew before taking steps to remove it. Sometimes dirt on paint, tile or wood also looks like mildew. To be sure if it is mildew, put a few drops of household bleach solution on the discolored surface. Mildew will bleach out in a minute or two but most dirt will not.
Mildew grows when it is warm, moist and dark.
Mildew grows on clothing, other textiles in the home, leather, books, paper, upholstery, mattresses, rugs, and wood. Treatment varies depending on the type of item or surface you need to clean. To remove mildew from clothing or other fabrics begin by brushing the mildewed area. It's best to do this outside. Dry the item in the sun if possible.