HIBISCUS
Queen of the Flowers

CHAPTER SEVEN

Growing Hibiscus in Containers
Although hibiscus are considered outdoor shrubs, the increasing number of apartment dwellers who have no garden space available and people who must limit their gardening has created a demand for information on how to grow hibiscus in containers. This information is needed not only by apartment dwellers living in colder climates where hibiscus are usually not grown, but by the ever-increasing number of those apartment residents in the warmer climates.

Soil mixes. Though hibiscus will grow in a variety of soils, they do best in soil mixes containing high levels of organic matter such as peat. A good hibiscus potting mix should never be heavy, but light and porous so that the water will quickly run through the pot and out the bottom. The mix should have a texture which will allow both water and air to pass through readily and yet retain some moisture. Hibiscus seem to do well in a mixture of two parts peat, one part fine pine bark, one part medium coarse sand and two parts soil, but other mixes consisting of peat, perlite, and coarse sand are equally good, but not as substantial.

Generally, native soils which are dug up outside are not ideal media for plants grown in containers. These soils need to be amended with compost, peat, bark, perlite and sand to improve their physical structure as in the case of sandy soils, for water and nutrient retention capacity. Native soils should be sterilized to kill disease organisms and weed seeds. Spread moist soil in a tray or pan and bake at 930° C (200° F) for 20 minutes, stirring every 5 minutes.

Packaged potting mixes can be bought at local nurseries and garden supply dealers. These materials are convenient and often have been sterilized to kill disease organisms and weed seed. Some packaged soils have been amended and are ready for immediate use. Others are primarily sterile soil which will require amending to make a desirable soil mix for container grown hibiscus.

Soil-less mixes consisting of various combinations of peat moss, perlite, and vermiculite are available at most garden supply dealers. These soil-less media are light weight, easy to handle, sterile, and most contain fertilizers. Growers who are using these new, soil-less mixes for their hibiscus in containers have had excellent results.

Plants can be grown in 40 cm (16 in) pots; however, larger containers are desirable: 40 cm (16 in) pots are large enough for a plant which is kept around 90 cm-1.5 m (3-5 ft) high. The plants should be pinched back when small to ensure good branching. Always leave the last leaf node on the outside so that new growth will point outwards.

Hibiscus pests are few and far between on patio plants. Sometimes aphids or spider mites will creep in from outside or be brought in on other plants or cut flowers. A horticultural spray can or garden type insecticide will usually take care of these. Usually there is no trouble with bud-drop, but leaves will sometimes turn yellow and this often is caused by lack of water. It is easy to forget to water plants, but they will remind you. If the plant drops its leaves, simply prune it back lightly and a new crop of leaves will come forth without further delay. Plants benefit by a weekly shower and this can be accomplished by mist spray, placing the whole plant in the bathtub with a tepid shower turned on gently.

Fertilizing. There are many special commercial materials available for fertilizing patio plants. Most are effective and safe if used as directed. A complete, well-balanced fertilizer should be used. Fertilizers are availabe in several forms - liquid, bead-like granules, tablets and water-soluble powders. The liquid and powder forms are diluted in water as directed and poured on the growing medium. The granules and tablets are designed to release nutrients gradually and evenly over a given period of time. The length of time these fertilizers are active will depend on the formulation of the material, temperature and watering practices.

Many patio hibiscus growers use a soluble fertilizer to feed their plants. Hibiscus plants may be fed a soluble fertilizer as often as once a week. when grown in pots. This may seem like a lot, but it is necessary to water them daily and this leaches away some of the nutrients. Then too, there is little or no dormant season for the well cared for patio plant and it may be kept in bloom the year round. If you use a well-balanced plant food you may expect to have blossoms that are well-coloured and quite large. Feeding too much nitrogen produces too much foliage and not enough flowers.

When you grow these tropical beauties on patios you will not have to fight the battle of nematodes, droughts, insects, frosts, or lack of any of the elements necessary for superior plants. Try hibiscus - they're fun!