Melaleuca alternifolia aka Narrow Leaf Paperbark

Melaleuca alternifolia is an evergreen shrub or small tree. Its common names include tea tree and narrow-leaved tea tree. It belongs to the myrtle family, Myrtaceae. It comes from Queensland and northeastern New South Wales, Australia. This plant grows in warm, moist subtropical areas. In the wild, it forms dense thickets in coastal swamps. It also grows inland at elevations up to 984 feet [300 metres].

Garden plants reach about 5–8 feet [1.5–2.5 metres] tall. Their spread is about 3–5 feet [1–1.5 metres]. Larger plants reach 20–23 feet [6–7 metres]. The RHS gives 10–20 years as the time to maturity. The bark is pale grey to white and papery. Smooth, narrow leaves look like needles and reach 1.2 inches long. They grow at uneven points or in whorls along stems. The leaves provide the oil known as tea tree oil.

Small white flowers appear in summer in dense, brush-like spikes. Insects pollinate them. Small woody fruits follow, each shaped like a cup. Seeds take about a year to develop. The woody capsules can stay on the plant for several years. Its evergreen leaves and pale bark give it value as an ornamental. Gardeners can grow it in patio pots, conservatories, or greenhouses. It also suits gardens in Mediterranean climates and sunny woodland edges.

Give it full sun and moist soil that drains well. RHS lists loam and sand, with acid, neutral, or alkaline soil. Useful Tropical Plants instead favours lime-free soil and reports some shade tolerance. Under glass, use peat-free, loam-based compost with added leaf mould. Give bright light, but shade it from hot sun. Water moderately during growth and less in winter. RHS recommends a balanced liquid feed each month during growth. Its UK rating is H2, so it needs protection from freezing. PFAF lists USDA zones 8–11. Prune after bloom when needed to keep indoor plants within bounds.

RHS reports few disease problems, though spider mites and scale may attack. Grow new plants from spring seed or summer semi-ripe cuttings. Tea tree oil has antiseptic uses and appears in soaps and deodorants. The wood lasts well in wet ground. PFAF lists no edible uses and warns against swallowing tea tree preparations. Reported effects include vomiting, diarrhoea, mouth irritation, drowsiness, and poor coordination. Useful Tropical Plants lists no known hazards, but this does not cancel that warning.