Hibiscus heterophyllus aka Queensland Sorrel

Hibiscus heterophyllus has two common names: native rosella and Queensland sorrel tree. It belongs to the mallow family, Malvaceae. It comes from Queensland and New South Wales in Australia. Its range spans the tropics and warmer parts of the temperate zone. It grows in moist eucalyptus woods and in gullies. It also grows at rainforest edges and in dry rainforest. Forest that grows back also provides a home.

This evergreen grows fast into an open shrub or small tree. Garden heights range from 6–10 feet [1.8–3 metres]. Broader accounts give heights of 5–20 feet [1.5–6 metres]. Older plants can lose some of their leaf cover. Cutting back by about one-third can help control this growth. Growers plant it for its blooms, including forms with yellow flowers. Insects pollinate the flowers. Each flower has both male and female parts. The seed capsules split open and let their seeds out.

Give it full sun and rich soil with plenty of humus. The soil should hold moisture but let excess water drain. It can grow in sand, loam, or clay soils. The soil can be mildly acid, neutral, or mildly alkaline. It also suits sites near water. PFAF lists USDA zones 9–11 but says frost can harm it. Useful Tropical Plants reports that it can bear brief frost near 23°F [-5°C]. Long cold spells can kill it. Plants with frost damage may grow back from lower branches. Plants from southern sources may cope better with frost. It may not live outdoors in Britain.

Sow seed in a warm greenhouse in early spring. In these conditions, seed tends to sprout soon. Move seedlings to their own pots when large enough to handle. Plant them outside in early summer. Give them shelter while they settle. You can also keep young plants under glass for their first year. Take half-ripe cuttings in July or August. Keep them warm through winter. In Britain, plants grown as annuals may flower in their first year. The stems also yield strong fibre for nets.

People eat the leaves, young shoots, flowers, buds, and young roots. Leaves and shoots taste sour; boiling makes them less sour. Flowers have a mild taste. Roots taste bland and have fibres and a slimy texture. These food uses do not prove that each way to prepare them is safe. Useful Tropical Plants links leaf tea to kidney damage. Hairs on the seed capsules can cause severe skin irritation in sensitive people. PFAF lists no known medicinal uses.