Bursaria spinosa aka Australian Blackthorn

Bursaria spinosa is an evergreen shrub or small tree. It belongs to the plant family Pittosporaceae. Its names include sweet bursaria, Christmas bush and Australian blackthorn. It comes from eastern and southeastern Australia, including Tasmania. Its range spans Queensland, New South Wales, Victoria and South Australia. It grows in woods, open ground and along riverbanks. It also grows on stony hills, but avoids arid sites.

The plant grows upright and has prickly stems. Garden sources give heights of about 10–15 feet [3–4.5 metres]. Some plants reach 33 feet [10 metres]. Its trunk is most often under 0.7 feet [0.2 metres] thick. The leaves stay on the plant all year. The flowers have a sweet scent and draw bees. Useful Tropical Plants lists butterflies and moths that pollinate it too. PFAF gives August as the bloom time. That source, though, refers to Britain. Each flower has both male and female organs.

Grow it in full sun with moist, well-drained loam. The soil should hold some water but not stay too wet. It accepts slightly acid, neutral and slightly alkaline soil. PFAF says it does not grow in shade. In British gardens, it needs warmth and shelter from winter cold. A wall that faces south or southwest can give this shelter. Only Britain's mildest areas suit growth outdoors. Reports from Australia note survival at about 19°F [-7°C]. It may not bear that cold through Britain's longer, wetter winters. PFAF lists USDA zones 7–10.

In mild climates, gardeners can grow it as a hedge. It also suits a sunny woodland edge or sheltered wall. Its flowers add scent and draw wildlife to gardens. It can help restore native woods by spreading onto open ground. This same trait can make it weedy on cleared land. Its hard, tough wood serves for tool handles and cabinet work. The leaves yield aesculin for medical uses and to screen ultraviolet light. These uses do not show that home remedies are safe.

PFAF lists no known food uses and no known hazards. This does not prove that every part is safe to eat. Sow seed in spring under glass. The seeds need no treatment first. Keep young plants under glass through their first winter. Plant them out in late spring or early summer. You can also raise plants from half-ripe cuttings. Gentle heat beneath the cuttings helps them root.