Hibiscus: A Plant That Blooms All Year
Hibiscus or Rose of China (Hibiscus rosa-sinensis) is a flowering plant that can bloom almost year-round. It has large, colorful flowers and is cultivated throughout the tropics and other warm climates.
Hibiscus vary in size. The normal height is 12 to 18 inches, but they can grow to as high as 5 feet if not cut back.
When buying hibiscus, look for plants that have lots of new buds and healthy leaves. Flowers appear where the leaves branch at the top of the stem and bloom for one to three days, depending on the plant variety. They have no distinctive fragrance.
Hibiscus should be watered often during the spring and summer growing season. They are dormant during the winter and should be kept at temperatures between 50 and 60 degrees. The plant cannot withstand extreme changes in temperature and humidity. Feed with liquid fertilizer at half-strength during active growth.
To stop a hibiscus plant from getting too big, cut it back in early spring and remove leggy growth.
The traditional method of cultivating hibiscus is to give the plant less food and water in October and November. Then cut it back, and put it in a cool place (about 54 F). This method yields a lot of blooms during the plantís growth period and none while it is dormant.
Keep hibiscus growing all year by regular watering, fertilizing and providing as much light as possible. Be sure to cut back leggy, leafless shoots.
February is the time to transplant your hibiscus to a larger pot. Use a good commercial potting mix, and gradually increase the amount of water.
In March and April, place it where the temperature is between 68 F and 75 F. Water frequently and add liquid fertilizer. Leaves and buds should develop rapidly. You can force some blooms by letting the plant dry out a little between waterings.
Dry heat from heaters can dry out or damage hibiscus. Add liquid fertilizer every six weeks. Remove withered blooms and clip back leggy growth.
Typical problems for hibiscus include aphids, spider mites, yellow leaves and bud drop. Aphids are often found on the tips of shoots and on the buds. They cause uneven, curling leaves and stunted growth.
Spider mites latch on the undersides of leaves. The leaves develop white or brown spots and finally wither and drop off. Fight spider mites by removing infested leaves and spraying with a miticide.
Yellow leaves are caused by root damage or by lack of water. They may also be the result of overfertilizing.
Bud drop is due to drafts, extreme differences in night and day temperatures or insufficient light.
Source: Dr. Dave Williams, Horticulturist, Alabama Cooperative Extension System, (334) 844-3032