Hibiscus syriacus

Hibiscus syriacus is a species of flowering plant in the mallow family, Malvaceae. It is native to south-central and southeast China, but widely introduced elsewhere, including much of Asia. It was given the epithet syriacus because it had been collected from gardens in Syria. Common names include the Korean rose (in South Korea), rose of Sharon (especially in North America), Syrian ketmia, shrub althea, rose mallow (in the United Kingdom), and rosa de Sharon (in Brazil). It is the national flower of South Korea and is mentioned in the South Korean national anthem. Hibiscus syriacus is a hardy deciduous shrub. It is upright and vase-shaped, reaching 2–4 m (7–13 ft) in height, bearing large trumpet-shaped flowers with prominent yellow-tipped white stamens. The flowers are often pink in color, but can also be dark pink (almost purple), light pink or white. Individual flowers are short-lived, lasting only a day. However, numerous buds produced on the shrub's new growth provide prolific flowering over a long summer blooming period. The soil in which the Hibiscus thrives on is a moist, but well-drained, mixture of sand, clay, chalk, and loam, maintaining an alkaline, neutral pH (5.5 – 7.0) level. Hibiscus syriacus is highly tolerant of air pollution, heat, humidity, poor soil and drought. Shoots make interesting indoor vase cuttings, as they stay green for a long time, and some new flowers may open from the more mature buds. The species has naturalized very well in many suburban areas, and might even be termed slightly invasive, so frequently it does seed around. The branches are thin and gray, white-lenticeled, with raised leaf scars and small buds. Stems and branches do not branch very much unless pruned, resulting in many long, straight stems that originate from about 0.5–1.5' above the ground, giving rise to the shrub's overall vase shape. The leaves appear unusually late in the season, in May. They are usually green or yellowish green, alternate, broadly ovate, palmately veined, and 3 in (7.6 cm) long. They have three distinct lobes with coarsely-toothed margins. H. syriacus has 5-petaled flowers (to 3″ diameter) in solid colors of white, red, purple, mauve, violet, or blue, or bicolors with a different colored throat, depending upon the cultivar. Extending from the base of these five petals is the pistil at the center, with the stamen around it. These basic characteristics give the H. syriacus flower and its many variants their distinctive form. The plant can bloom continuously from July through September, usually at night. The 4 in (10 cm) wide, single- or double-flowering, large-petaled, very showy flowers adorn the plant throughout the summer. With maturity, flexible plant stems become weighted under the load of prolific summer flowers, and bend over halfway to the ground. Most modern cultivars are virtually fruitless. The fruits of those that have them are green or brown, ornamentally unattractive 5-valved dehiscent capsules, which persist throughout much of the winter on older cultivars. They will eventually shatter over the course of the dormant season and spread their easily germinating seeds around the base of the parent plant, forming colonies with time. Though it has no fall color and can be stiff and ungainly if badly pruned, H. syriacus remains a popular ornamental shrub today, with many cultivars. Full-grown plants can tolerate a wide range of conditions, including frost, drought and urban pollution. However, the best results are produced in a warm, sheltered position; a well-drained neutral soil; and full sun. Hibiscus syriacus is fairly easily propagated from either seeds, with variable results, or by layering or cuttings, cloning the original. Old shrubs can develop trunk cankers that may eventually prove fatal to the plant. The plant has some susceptibility to leaf spots, blights, rusts and canker. Japanese beetles, whiteflies and aphids are occasional insect visitors. Japanese beetles can severely damage foliage if left unchecked.