Melaleuca linariifolia aka Cajeput Tree

Melaleuca linariifolia is an evergreen shrub or small tree. It belongs to the myrtle family, Myrtaceae. Common names include tea tree and flax-leaved paper-bark. Kew places its native range in eastern Australia. This includes New South Wales and Queensland. It grows in coastal swamps and other wet sites. It also grows on coastal plateaux, sometimes over shale.

Garden descriptions give heights of about 20–30 feet [6–9.1 metres]. One source gives a taller limit of 33 feet [10 metres]. A shrub form may spread 13 feet [4 metres]. Trees have a stout trunk and a rounded crown. Thick, spongy bark peels away in layers. Its shades range from grey and chalk-white to reddish brown. Young twigs are reddish brown and turn grey with age. The stiff, narrow leaves are grey-green on both sides. They grow one at a time along the stems. Each leaf has parallel veins and a short stalk.

White flowers form brush-like spikes at the branch tips. Long stamens give each spike its soft outline. Heavy bloom can hide much of the crown. Virginia Tech records flowering from May to June. The flowers have a scent, and insects pollinate them. Small, woody capsules hold many tiny seeds. The seeds take about a year to mature. Capsules may stay on the plant for three years or more.

Grow this plant in full sun and moist soil. It needs soil that holds water but drains well. Sources favour fertile, lime-free soil without high nitrogen levels. Sandy, loamy and clay soils can all suit it. Reports differ on how much shade it will accept. Establishment can be difficult, and seedlings may suffer damping-off. Prune after flowering to keep the plant compact. Sources report brief frost tolerance near 23–19°F [-5 to -7°C]. Warm summers help the wood mature before cold weather. These limits do not ensure survival through a British winter. Only the mildest British sites are likely to suit outdoor plants.

Gardeners grow it as an ornamental plant and a hedge. Its bark and dense flowers provide much of its appeal. The wood lasts well in wet ground. Leaves and twigs yield an oil with reported antibacterial uses. Sources list no edible uses. Safety reports differ: one lists no known hazards. PFAF warns that swallowing it can cause gut and nervous-system effects. Do not take it internally.