Hibiscus, Hibiscus Flower Pictures, Rose of Sharon

Hibiscus

Hibiscus, genus of plants, also commonly called rose mallows, of the mallow family. The genus is native to warm, temperate regions of the Northern hemisphere. The hibiscus flower is characterized by a five-pointed calyx (set of sepals) that is surrounded by a set of coloured bracts growing just beneath it, giving the appearance of a double calyx. The large, showy flowers have five petals, a column of fused stamens with kidney-shaped anthers, and several pistils. The fruit is a many-seeded, five-celled pod. hibiscus diseases

Rose of Sharon is a tall asian shrub with smooth leaves. Cultivated varieties have open, bell-shaped flowers in colours ranging from white to yellow, rose, red, and purple. The Chinese hibiscus, or China rose, is a shrub or tree that grows as tall as 9 m (30 ft) but is also sold as a pot plant. It produces huge, showy flowers. Many species, such as mahoe, Cuban bast, and a species with yellow and purple-red flowers, have economic uses. all three are used for fibre, and the third is a source of wood for cabinetmaking.

Propagation

Most tropical hibiscus were propagated by rooting/cuttings. Some varieties are easier than others to root. Many growers use a perlite rooting medium in plastic pots. using a rooting hormone usually helps and it is very important never to let the medium dry out. Putting 15 or 20 cuttings in a 6" pot is common and, depending on temperature and lighting conditions, these may root in 6 to 8 weeks. Warm temperatures, high humidity and adequate light are important. air-layering is also used for propagation.

Hybrids are usually grafted to rootstock varieties that have proven themselves to be resistant to soil borne problems and have a strong root system. Hybrids may or may not root easily and their root systems may or may not be vigorous. Every year there are new hybrids and the most effective way to get these new varieties to the public is to graft.

To graft, a sharp knife is used to notch the rootstock and expose the cambium layer below the bark. a sliver of the hybrid with an "eye" is trimmed to expose its cambium layer and inserted into the notch to match-up with the cambium layer of the rootstock. This area is then wrapped with a rubber strip to keep tight and then sealed with grafting wax. To see a pictorial explanation, please visit this excellent australian site. after viewing the australian site, a slight variation can be seen here.

Raising hibiscus from seeds is another means of propagation. This is how new varieties are developed. When pollen is applied to the female pads and a pod forms, it is usually a couple of months until the pod ripens and exposes its seeds. Getting a pod to form on a plant can be very difficult -- 60-80F degrees, high humidity and "willing" parents. after the seeds have germinated and been raised to maturity, 6 to 18 months, they will produce a flower (and bush) with qualities from both the pollen and the pod parent. Some of these flowers may be spectacular and some may be inferior to their parents. The flower produced by that seedling is genetically unique and until rooted or grafted is the only plant capable of producing that particular flower.

Scientific classification

The genus Hibiscus belongs to the family Malvaceae. Rose of Sharon is classified as Hibiscus syriacus, the Chinese hibiscus, or China rose, as Hibiscus rosa-sinensis, and mahoe as Hibiscus tiliaceus. Cuban bast is classified as Hibiscus elatus, and the economically useful plant with yellow and purple-red flowers as Hibiscus macrophyllus.

Types

There are many types (species) of Hibiscus. The most popular ones are:

• Hibiscus brackenridgei (Hawaiian hibiscus)
• Hibiscus rosa-sinensis (Chinese hibiscus)
• Hibiscus syriacus (Garden hibiscus)

Fertilizer

Fertilize lightly and often -- hibiscus are heavy feeders. use fertilizers that include the trace elements such as iron, copper, boron, etc. a dry fertilizer such as a 10-10-10 is all right, however most growers prefer low phosphate fertilizer such as a 7-2-7, feeling that it helps produce the most impressive quality and quantity of blooms. Those so-called "bloom specials" with the 10-40-10 type of formula are avoided by most professional growers -- phosphorous can build up in the soil over time and cause a general decline in the health of tropical hibiscus plants. Over-use of high nitrogen fertilizers may encourage leaf growth rather than flower production. Water soluble fertilizers are good both for spraying leaves (foliar feeding) and for fertilizing potted plants. (High phosphorous water soluble fertilizers can be used successfully when applied as a foliar feeding.) Experiment and see what works well for your local growing conditions. Slightly acid soil (a pH of 6 to 7) helps the plant absorb nutrients. Hard water and proximity to things like concrete can move the pH in the wrong direction -- toward an alkaline pH.

Punning

Pruning is used to shape future growth, invigorate old plants, manage plant size and get rid of diseased and dead wood. While the tropical hibiscus can be pruned any time, probably the ideal is the earliest where the resulting tender new growth will be safe from cold damage*. For shaping purposes, some growers will prune the longest third of the branches and return in 4 to 6 weeks and prune the next longest third. Only sharp, clean shears should be used. a clean cut should be just above and angled down and away from an "eye" or node. (a node is the junction of a leaf and the stem. There is a small bud in this junction that is activated after pruning.) Cutting above outward pointing "eyes" will encourage growth in that direction. The new growth resulting from pruning invigorates the plant and will provide a source for many new blooms.

Insects

Insects, such as aphids, thrips, scale, whiteflies, etc. should be checked for frequently. Water plants thoroughly before using insecticides to lessen shock. It's usually best to apply in the early morning or in the evening when temperatures are below 80F degrees. When applying, both the tops and undersides of the leaves should be sprayed. Of course, follow the label directions. For most insect problems, Orthene, a systemic, is widely used. Cygon, another systemic, is often used against scale and other insects. Products containing imidacloprid are excellent for controlling whiteflies. Many people report that bounce fabric conditioner strips also discourage whiteflies. Soaps and dishwashing detergents (Soaps are preferable to detergents.) are also very useful as are certain types of oils, such as ultra Fine Oil, very good for whiteflies. Many report good results with neem products. WD40 or Pam, sprayed on the stem and branches and avoiding the leaves, are excellent for controlling scale. NEVER use liquid Malathion on hibiscus. For help in identifying your insect problem, please visit these two australian Web sites --- one and two. For great information on insecticides, visit this uF page. Here's a page dealing with the pink mealy bug.

Hibiscus often become national/state flowers. For example, the Hawaiian hibiscus is the state flower of Hawaii.