Family: Asclepiadaceae

Most of the 200 or so species of this genus of succulents are climbers. They have a broad dis­tribution from China and India, through Malaysia and Australia, to the islands of the South Pacific. Hoyas have fleshy, leathery, sometimes shiny leaves and clusters of fragrant, star-shaped flowers in white, cream, yellow, pink or red in spring to summer.

Species

H. australis, wax plant, from Queens-land and Fiji, has slender, twining stems, pairs of thick, shiny, oval, dark green leaves, 5-8 cm (2-3 in) long, and small, white flowers with red centers.

H. carnosa, the most commonly grown species, is a native of China and India. A twining species, it has thick, fleshy leaves, to 9 cm (3½ in) long, and dense clusters of long-lasting, white or pale pink flowers with pinkish red centers. Variegated leaf forms are available.

H. lanceolata subsp. bella, from India, is a shrubby species, with thin, drooping branches, up to 45 cm (18 in) long, and pairs of small, pale green, elongated, heart-shaped leaves. The clusters of small, waxy, white flowers, with pur­plish pink centers, last about a week.

H. macgillivrayi, from the very north of east-em Australia, has striking large red flowers, to 6 cm (2½ in) across, in umbels of six to ten flow­ers.

H. rubida, coming from the same area, has bright green, ovate leaves, to 12 cm (5 in) long, and waxy, dark red flowers, to 4 cm (1½ in) across. The fruit is long and thick.

Cultivation

In frost-prone climates, hoyas are grown in a warm greenhouse or conservatory, except for H. carnosa, which is best in cool conditions. Grow in pots of soil-based potting compost, enriched with shredded bark and leaf mould. Plants need good light but should be shaded from direct sun, and they like a humid atmosphere. The climbers will need support of some kind. Climbers can he lightly pruned after flowering. Propagate from semi-ripe cuttings in summer, rooting them in a heated propagating case, or by layering in spring.

Climate

Subtropical to tropical; at least zone 10.