Mike, did you pull the root-ball out of the pot and see whether the plant was root-bound? If the roots are circling the pot again and again, and there are now more roots than there is soil, you need to repot the plant(s) in a larger pot. Before re-potting, be sure you loosen some of the root mass so that it will not continue growing in a circle. Hibiscus are not only heavy water users but are heavy feeders. The larger the pot the better. Generally they are more accustomed to be found in the landscape, rather than potted because of those two factors alone. Ken
