Grace Cary

Queen of tropical flowers, the hibiscus is flamboyant and colorful and reminds us of warm, distant climates when temperatures drop. Flowering in late summer and fall, there are tender forms to enjoy in a greenhouse, as well as hardier plants to grow outdoors.

There are 437 species of hibiscus, mostly native to tropical and subtropical regions, particularly the coast of the Indian and Pacific Oceans, where the large flowers adorn temples and shrines. The most iconic of all – Hibiscus rosa-sinensis – was introduced to Europe in 1731, and in the 18th and 19th centuries its flowers became the symbol of all things exotic.

The genus encompasses a range of plant types, from low perennial herbaceous plants to shrubs and even large trees. A red tea is made from the garnet calyxes of the subshrub Hibiscus sabdariffa (roselle) and drunk in many parts of the world, hot or cold. It is rich in vitamin C and other nutrients and has a tart taste similar to cranberries.

But the two hibiscuses that most interest gardeners are H. syriacus And H. rosa-sinensis, the two shrubs. H. syriacus is the hardiest and can be grown outdoors in the milder parts of the UK; Its common names are rose of Sharon and Syrian hibiscus, but these are misnomers, since the plant is native to China and not coastal Israel or Syria. Under good conditions it is long-lived and drought tolerant and produces large pink, red, blue or white flowers in late summer and autumn.

H. rosa-sinensis (Chinese hibiscus) is a fabulous tender plant for a conservatory or greenhouse. It has been cultivated as an ornamental plant in China for thousands of years and is the best-known hibiscus. The large, letterbox-red flowers with long, gold-tipped anthers are synonymous with Hawaii and Florida, where the plant has been widely used as a parent to create some 10,000 hybrids, including yellow, peach, white and pink forms. A collection of Chinese hibiscus hybrids was recently added to the large greenhouse in RHS Wisleydemonstrating how to grow them under cover. They are easy to grow in pots or greenhouses and, in the right conditions, can flower for several months, injecting much-needed color and vibrancy of the tropics on gray days.