Backhousia myrtifolia aka Myrtles

Backhousia myrtifolia, or grey myrtle, is an evergreen shrub or tree. It belongs to the myrtle family, Myrtaceae. Its native range runs from southeast Queensland into New South Wales. It grows in gullies and along the edges of rainforests. Kew places it in the subtropical climate zone. These habitats help explain its preference for moist growing conditions.

Plants For A Future gives a height of 39 feet [12 metres]. It does not give a separate size range for garden plants. The plant keeps its leaves throughout the year. Its leaves yield an essential oil, though the source names no use. The wood is hard, strong, tough, and close-grained. People have used it for tool handles, wheels, and building work.

Plants For A Future records flowering in May. Each flower has both male and female organs. Seeds can stay viable on the plant for three to four years. The supplied sources give no details of fruit shape or colour. They also give no account of bark or leaf shape. The plant has value as an ornamental and a scented garden plant.

Choose full sun and fertile soil that holds moisture but drains well. Sandy and loamy soils suit this species. It accepts mildly acid, neutral, and mildly alkaline soil. Plants For A Future says it cannot grow in shade. The same source lists USDA zones 8–11. In Australian gardens, plants have survived at least 19°F [−7°C]. This does not prove equal hardiness in Britain. Cooler summers and longer, wetter winters can change the outcome. The source regards only the Scilly Isles as reliably suitable in Britain.

To raise plants from seed, sow on the surface in spring or autumn. Use a greenhouse and keep the compost moist until seeds sprout. Move seedlings into their own pots once large enough to handle. Keep them under glass through at least their first winter. Plant outside in late spring or early summer after frost risk passes. Half-ripe cuttings with a heel offer another route in July or August. Plants For A Future lists no known edible or medicinal uses. It reports no known hazards, but this does not establish safety. It also reports no weed potential. The supplied evidence identifies no specific pests or diseases.