Hibiscus belongs to the family of large showy flowers, and has more than 200 species that grow world over in warm, temperate, subtropical and tropical climates. Hibiscus includes many varieties; annual and perennial herbaceous plants, and woody shrubs and small trees. Most hibiscus shrubs are perennials, that usually don't survive extreme winters. These flowers do wonderfully if you live in zones that are frost free. So to ensure a beautiful bloom, hardy hibiscus have to be cultivated from wild native hibiscus flowers, that have the largest flowers borne on them. With some basic winter care, they can be marginally grown in zone 3 also. Their needs don't differ much. The hardy hibiscus plant is botanically known as Hibiscus moscheutos. They are also known by their cultivators, the Fleming Brother's name, Fleming hybrid hibiscus.
Their dull green foliage are heart shaped and the flowers are big in size, and the texture of the petals is fine and delicate, almost papery thin. There are some varieties of these plants that have small flowers too, with the flower size ranging anywhere between 3 to 4 inches to 8 to 12 inches in diameter, which makes them easier for care. In the center, depending on the size of the flower, there is a prominent pistil and stamen. The basic difference between a hardy and a tropical hibiscus is the color of the foliage; hardy is dull green, whereas tropical is glossy dark green. Until a few years ago, hardy hibiscus varieties were only available in red, pink, and white. However, due to hybridization, they now come in an array of vibrant colors; red, white, lavender, purple, pink, magenta, yellow, etc. Even ruffled edges, bi-colored and dark veined varieties are available now. The flowers begin to bloom mid-summer and continue until frost sets in.
Caring for it
Hardy hibiscus can be propagated from seeds and cuttings. But while gardening, seeds take longer time to germinate and should be kept warm, or else it affects the flowering later. Buy your hardy sapling from a nursery, or try some grafting techniques. Many new introduced varieties that offer smaller, lobed leaves and more compact plants, some even with dark, reddish foliage are also available. The best time to plant them is during early spring or summers. They prefer full sun, fertile and well-drained soil. This is very important for their care, as soil that retains excess moisture should be avoided. The pH balance of the soil should be maintained between 6.5 to 7.0. Organic compost should be used. Use fertilizers during their growing and flowering period, every 15 days. If you want to make the plant more bushier, pinch back the main growth. This will speed lateral growth. Winter care for this plant basically involves keeping the plant warm, and then moving them indoors. A thick layer of mulch over the plant roots, should be done before the onset of winters to keep the plant roots from freezing. They are quite resistant to pests and insects, and only a few, like aphids and mealybugs get to them and they can be easily removed using specific pesticides.
Hardy hibiscus does not require heavy pruning. Pinching back to make the growth more bushier when they are young, will train the plant to grow in the size and shape you want. As they are herbaceous perennials, their top branches fade and fall to the ground each winter. New shoots sprout during spring from the soil and the branches. Prune back diseased or dead branches, even crossing branches, especially if they tangle the plant.
Care required for this plant is minimal compared to many other plants and trees. They bear flowers that are amazingly beautiful, which are a constant delight to the eyes.