Hibiscus are known for their large, colorful blossoms. They are also called tropical hibiscus and Chinese hibiscus. Hibiscus is a deciduous shrub or small tree, and when mature the hibiscus can reach a height of up to 15 feet. Blossom colors include yellow, peach, or red--some blossoms can be 6 inches in diameter. Hummingbirds and butterflies are attracted to the lovely blooms. Care of the hibiscus is average, and the easiest method of propagation is by seed.
Propagation by Seed
Growing hibiscus from seed is the easiest method of propagation. However, it does take longer than propagation through cuttings. To grow a hibiscus from seed, place two seeds in a shallow container of starter mix. Water the seeds well, and keep the mix moist but not wet. Keep the container out of the sun but at a temperature of 68 to 77 degrees Fahrenheit. Within three weeks the seedlings will appear. Seedlings can be potted when they reach 8 inches in height. Flowering will begin in five to 12 months.
Root cuttings can be taken in late winter to early spring. Select a hardwood stem for the cutting. The stem should be straight and free from blemishes (about the diameter of a pencil or slightly thicker). Make a 45-degree cut just below where leaves/buds join the stem, and trim the cutting down to about 5 to 6 inches. All leaves should be removed. The stem is then placed in a pot of coarse material (sand or perlite, and 1/2 peat). Several cuttings can be placed in the same pot. Keep the cuttings moist and place them in partial sun--temperatures should be 70 to 85 degrees F. Rooting will take place in six to eight weeks.
Care of the Hibiscus
Hibiscus can be planted in the landscape or they can be grown in containers. They will require a site in full sun with well-drained soil. Watering requirements are approximately 1 inch of rain or water per week. In the growing season, hibiscus should be fertilized twice a month. You will need to prune to remove any dead, diseased or damaged branches as well as to maintain shape and size. This plant is very sensitive to cold temperatures; hibiscus should be protected when temperatures are in the 30-degree F range.
Aphids and the Hibiscus
Aphids are a pest that can infest the hibiscus plant. They are small insects--also called plant lice. Aphids feed on the hibiscus, and are normally found on the upper part of the stem of the plant around the flower buds. These tiny insects vary in color (green, white, yellow, brown, red or black). As they feed on the plant they secrete honeydew, a waste material. Black sooty mold can grow on the honeydew, which further detracts from the appearance of the hibiscus plant.
Normally, the natural predators of aphids (ladybugs and lacewings) are able to control the aphid population. If you have aphids on a single branch you can prune out the infested branch. Be sure to destroy the infested plant material--do not put it in your compost bin. For a severe infestation of aphids, the National Gardening Association recommends that you control them by using a horticultural oil or insecticidal soap. The insecticide imidacloprid can be used as a soil treatment. Imidacloprid is toxic and a contaminant to both soil and surface water.