While teak furniture is extremely mold and mildew resistant, it is possible for spots to appear. Use a solution of diluted bleach to clean the mold or mildew. If there are only a few small spots, you can spot clean with a sponge or soft brush. It the problem is on a larger area, spray on the diluted solution, let it sit for a few minutes and rinse off with water, completely.For more information, click Removing Mold and Mildew from Teak Furniture.