Hoya linearis aka Hanging Wax Plant

Hoya linearis is an evergreen plant in the Apocynaceae family. Its native range stretches from Nepal to northwestern Yunnan, China, and Indochina. Kew lists it as a subtropical, epiphytic subshrub. The RHS calls it the slender wax flower. It is not native to Britain or Ireland. Gardeners grow it as a trailing houseplant.

This semi-succulent perennial has thin stems that hang down. Fleshy, linear leaves grow in opposite pairs along them. Each leaf can reach about 2 inches (0.05 m) long. The narrow leaves give the trailing stems a fine outline. Cultivated plants reach about 3.3–4.9 feet (1–1.5 m) in height. Their spread ranges from 0.3–1.6 feet (0.1–0.5 m). The RHS gives five to ten years to reach full size. Its trailing form suits a hanging basket, conservatory, or greenhouse. The leaves remain on the plant through the year.

Flowers may appear in late summer, though flowering is not assured. The white blooms have a star shape and carry scent. They form clusters of ten to thirteen flowers. These pale clusters contrast with the plant's long, narrow leaves. The species profile gives no details about its fruit. Its hanging growth and scented flowers provide its main ornamental value.

Grow it in bright light, screened from strong, hot sun. Use peat-free compost based on loam, with extra organic matter. The mix should let excess water drain away fast. The RHS lists both loam and sand as suitable soil types. It also accepts acid, neutral, and alkaline conditions. Water moderately while the plant is in active growth. Give a balanced liquid feed once a month during this period. In winter, keep the compost only slightly moist. The RHS rates its hardiness as H1B. This allows summer outdoor growing in warm, sheltered conditions. The rating gives a temperature range of 50–59°F (10–15°C).

The RHS includes this species among low-maintenance plants. Mealybugs can attack it, but disease is not a usual problem. Prune after the flowers have finished. Propagate by layering in spring or summer. Semi-ripe cuttings offer another route in late summer. Supply heat beneath these cuttings to help them root. The supplied species evidence does not establish edibility or toxicity. It therefore gives no basis for treating any part as food.