To effectively clean mildew off outdoor furniture cushions, start by removing the cushions and taking them to a well-ventilated area. Brush off any loose debris or spores outdoors to prevent spreading mildew inside. Create a cleaning solution by mixing equal parts white vinegar and water in a spray bottle—the acetic acid in vinegar naturally kills mildew. For tougher mildew, make a paste from baking soda and water, or use a mild soap like dish detergent with warm water.
Apply your chosen cleaner generously to the mildewed areas and let it sit for 10-15 minutes to penetrate the mold. Use a soft-bristled brush to gently scrub the fabric in circular motions, focusing on stained sections. Avoid harsh scrubbing that could damage the fabric. Rinse thoroughly with a hose or clean cloth and cold water to remove all cleaner residue.
After cleaning, ensure cushions dry completely before storage or use. Place them in direct sunlight if possible, as UV rays help kill remaining spores. Flip cushions during drying to ensure all sides dry fully. To prevent future mildew growth, store cushions in a dry, well-ventilated area when not in use, and consider applying a fabric protector designed for outdoor materials. Regular cleaning every few weeks during damp seasons can also inhibit mildew development.