The leaves of my giant hibiscus are turning white. I have tried fertilizer. I have had this planted in my yard for 4 years.
Leaves of Giant Hibiscus Turning White
Certified GKH Gardening Expert
Most likely this is sunscald, which is like sunburn in plants. It will normally right itself. If the white on the leaves is powdery in nature rather than in the leaves themselves, it could be powdery mildew. This can be treated with neem oil.