Hibiscus, also known as rose of China, is a tropical plant with glossy leaves and distinctive, vividly colored flowers that can be pink, red, yellow, orange or snowy white. Hibiscus plants are well-suited to life as houseplants. Although people sometimes move them outside onto patios for the summer months, a hibiscus can do very well living indoors year-round. By following a few simple guidelines, you can make sure that your potted hibiscus plant will thrive indoors, where it will enliven any decor with its bright blooms.
Ensure that your hibiscus will flourish and blossom by placing it in a sturdy pot filled with potting soil and putting it in a location that is moderately warm, free of drafts, and exposed to several hours of direct sunlight daily. A window seat in a window facing south or west is a good choice. Provide supplemental light in wintertime with fluorescent bulbs placed as close to the plant as possible.
Watering and Fertilizing
To duplicate the effect of warm tropical rains, use lukewarm water, especially in winter. To prevent root rot, allow soil to dry out between waterings. If excess water remains in the planter for more than half an hour, you are over-watering. Encourage flowering by feeding your hibiscus with a water-soluble fertilizer that is low in phosphorus, such as a 20-5-20 NPK formulation. During your plant's growth period--normally March through October--you can fertilize every time you water; once in a while, use only plain water in order to discourage salt buildup in the pot. To avoid damaging roots, never fertilize a hibiscus that may have dried out due to under-watering; first put the pot in a bucket with water about 2 inches deep for half an hour, then return the pot to the planter. If the soil feels moist, you can then water and fertilize.
Although some yellow leaves are normal on a hibiscus, numerous yellow leaves may be a sign of spider mite infestation. Examine the plant, especially the undersides of leaves, for signs of any tiny, reddish-black spiders or wispy-looking webs. Eliminate spider mites by blasting the plant weekly with forceful sprays of lukewarm water. If the problem persists, spray plant with a solution of nontoxic insecticidal soap made by mixing 2 tsp. of castile soap per gallon of lukewarm water. Aphids--tiny, teardrop-shaped insects--also can infest your hibiscus. Like spider mites, they can be controlled with forceful spraying and a mild insecticidal soap.
Tips and Precautions
Never turn a hibiscus that is in bud; this can cause the buds to fall off. If a hibiscus in bud must be turned in order to balance out growth, swivel it slowly, making a quarter-turn every few days. Check your hibiscus every spring to see if it needs re-potting, and check roots to see that they are white to tan in color, firm and flexible. Cut away any dark brown, black or mushy-feeling roots. Also check for signs that the soil may have compacted in the pot; if this is the case, re-pot using coarser potting soil. To establish a well-shaped plant and promote flowering, prune your hibiscus in the fall. Remove weak growth or sideways-growing branches, and cut back branches, making cuts right above buds if possible.