The best way to clean mildew from the crevices of your outdoor furniture involves a few key steps. First, take the furniture outside on a sunny, dry day. Brush away any loose dirt or debris. For a safe and effective cleaning solution, mix equal parts white vinegar and water in a spray bottle. For tougher mildew, you can use a diluted bleach solution (one part bleach to four parts water), but test it on a small, hidden area first and use caution.
Spray the solution generously onto the mildewed crevices and cushions. Let it sit for 10-15 minutes to penetrate and kill the mildew spores. Then, use a stiff-bristled brush (an old toothbrush works well for tight spots) to scrub the crevices thoroughly. Rinse the furniture completely with a garden hose. Finally, allow it to air dry completely in the sun before using or storing it. To prevent future mildew, store cushions indoors when wet and cover furniture during prolonged rainy seasons. Regular cleaning with a mild soap solution can also inhibit growth.