Description
Hibiscus – Giant Mallow – Mallow – Rose Mallow –
There are about 220 species of deciduous and evergreen shrubs, trees, annuals and herbaceous perennials, in this genus. They are widely distributed in warm temperate, subtropical and tropical regions, where they occur in a variety of habitats, including stream side, moist woodland, and dry, rocky sites. They have alternate, smooth edged or shallowly to palmately lobed, sometimes toothed leaves, and are grown for their showy, 5 petaled, mainly funnel shaped, held solitary or in clusters, borne over a long period from spring to autumn. The flowers are red, pink, purple, blue, yellow or white and sometimes have contrasting marks at the bases of the petals, and prominent, colorful stamens. Grow in a sunny mixed, herbaceous, or shrub border. Some perennials may be grown as annuals or hedges.
Outdoors, grows in humus rich, moist but well drained, neutral to slightly alkaline soil in full sun. Hibiscus need long, hot summers to flower well. Trim after flowering to maintain shape. Most are drought and frost tender.
Prone to rust, fungal leaf spots, bacterial blight, Verticillium wilt, viruses, stem rots, root rots, whiteflies, aphids, mealybugs, scale insects, mites, Japanese beetles, and caterpillars.
H. heterophyllua – Austrian Native Rosella – Scrub Kurrajong – A free flowering, tall, open evergreen shrub or small erect tree native to Eastern Australia, growing 10-20′ feet tall and half as wide. It has prickly branches and narrow, pointed, heavily veined leaves which on young plants deeply 3 lobed. In the Southern part of its range, flowers are usually white or pale pink with a deep purple eye, borne in summer and fall.
Subsp. luteus – with yellow flowers is more usually in Northern parts of its range with darker centers
Zones 10-12