Hibiscus comes in two types: tropical and perennial. Both are beautiful plants, but they have individual needs regarding fall care and preparation for winter. Perennial hibiscuses are very hardy and have few fall requirements. Tropical hibiscuses require protection in extreme climates. Knowing which type of hibiscus you have can be tricky because most greenhouses and garden centers do not distinguish between them. Once you figure out which type you have following the procedures to care for your hibiscus is easy and your plants will give you a lot of enjoyment.
Determine which type of hibiscus you have. Tropical hibiscus have glossy green foliage and small to medium sized (3 inches to 6 inches) single or double flowers. Beware of some hybrid tropical varieties that grow up to 10 inches in size. Color is yet another indication of type. Only tropical varieties come in peach, yellow, orange or salmon. If flowers are the size of a dinner plate, have dull green leaves and stems and are not the above-mentioned colors they are likely perennial (hardy) hibiscus. When in doubt err on the side of caution, consider the plant a tropical because treating a perennial hibiscus like a tropical will not harm it in any way, while treating a tropical like a perennial in the winter will likely kill it.
Treat your perennial hibiscus to a good covering of mulch. The plant will die back to ground level and re-emerge in the spring without much help.
Cut back your tropical hibiscus with a strong pair of garden sheers to a few inches from the main stem. This removes any dead leaves and stalks and helps prevent mildew. It also gets rid of any bugs that tend to hid in the outer layers of plant material and keeps them out of your house.
Wash the plant thoroughly before you bring it inside. Use a hose and run water over the leaves and stems of the plant. Let it dry completely.
Water the plant very lightly during the winter months. Soak it when the soil is completely dry. Keep water from pooling in the reservoir. Leaves will die off. That is the normal cycle and they will return in the spring.