Because Outdoor furniture cushion is stored on the outside. furniture has problems of unprotected and directly exposed to sunlight. There are five tips for protecting outdoor furniture cushion:
1. Choose a durable, weatherproof, material when buying your outdoor furniture cushions.
2. Weatherproof your cushions with a waterproof silicone spray to help protect them from mold and mildew
3. Cover the cushions with clear plastic to keep them completely free of moisture.
4. Put your cushions in the garage on rainy days if possible. If you do not have indoor space, stack the furniture if it is a stackable variety.
5. Clean your cushions regularly with a cleaner that helps keep the fabric free of mold and mildew

some of the tips above can be tried