There are three types of hibiscus flowers, each of which has distinct growing preferences. Whether you choose to grow the tropical Hawaiian-style hibiscus or the giant hardy hibiscus flowers, they're rewarding, blooming repeatedly throughout the season and thriving with little attention. Your gardening zone may determine which varieties you can grow and how much maintenance they will need.
The state flower of Hawaii, tropical Hibiscus is a perennial in its native environment, but because of its bright and vibrant colors, it is often grown as an annual in colder areas. Growers recommend light and frequent fertilizing, because the hibiscus is a heavy feeder, naturalized in areas with rich soil that's well drained and high in nutrients. Pruning can help encourage new growth. Hibiscus growers have devised a few methods for pruning; some growers recommend trimming down 1/3 of the plant every 4 to 6 weeks so there's always mature growth. Tropical hibiscus thrives in full sun to partial shade.
Rose of Sharon
The rose of Sharon is a hardy, easy-to-grow shrub. It blooms from late summer to mid-autumn and, in proper conditions, can thrive without attention or special care. Pruning can help prevent overgrowth or keep the plants compact for small spaces. They bloom in shades of red, pink and white. The size of the bloom will depend upon pruning. A plant that is pruned more often will produce fewer, larger blooms, whereas a plant that's left wild will produce more, smaller flowers.
In the early years, this plant will need protecting from harsh winter elements. Placing a layer of straw or soil on top of the root base and pruning at the end of the growing season can help protect the young plants. After their third year, they're generally hardy enough to handle freezing winter temperatures. Plant in an area that's mostly sunny. The soil quality can vary, as long as it doesn't stay extremely wet.
The hardy hibiscus grows the largest flowers, with blooms that can get to be 8 inches across. Although each flower lives only for one day, the plant generally produces hundreds in one season. Hardy hibiscus prefers 5 to 6 hours of sunshine a day and tolerates a much wetter soil.
True to its name, growers in colder regions can have great success with hardy hibiscus. They may need protection during their first winter; prune down to the root base and cover with straw or rotting leaves. A hardy hibiscus is a late bloomer, with green shoots that don't begin to show until late in the spring or early summer, and the first flowers appearing late in the summer. They continue to flower until the frost kills the last of the buds.