Sorbus austriaca

Sorbus austriaca is a deciduous tree in the rose family, Rosaceae. Its native range runs from Switzerland to Austria and Hungary. The RHS lists it as non-native to Britain and Ireland. PFAF gives a height of about 33 feet [10 metres]. It sheds its leaves each year. The sources give no species-level details on leaf shape or bark. PFAF places it close to Sorbus intermedia.

Flowers appear in May and June, and insects pollinate them. Each flower has both male and female organs. Seeds ripen from September to October. The fruits grow in large clusters and measure about half an inch across. Fully ripe fruit has a mild, partly sweet taste. Its flesh has a mealy texture. You can eat the fruit raw or cook it into preserves. PFAF records heavy fruit crops at Wisley and Cambridge Botanic Garden.

Grow this tree in an open, sunny site. It accepts light shade, but sun helps it bear more fruit. It suits a sunny woodland edge or a woodland garden. It grows in most good soils, including sand, loam and clay. The soil should stay moist but drain well. It accepts mildly acid, neutral and mildly alkaline soil. It withstands strong winds, but not exposure to sea winds. PFAF lists USDA zones 5–9 and describes it as frost hardy. Fireblight is a known disease risk.

Seed offers a way to raise new trees. Sow fresh seed in a cold frame once it ripens. An outdoor seedbed also works when enough seed is available. Stored seed benefits from two weeks of warmth before cold treatment. The cold stage lasts 14–16 weeks. Move seedlings into separate pots once large enough to handle. Early shoot growth stays slow for one or two years. During this time, young plants develop their roots. Keep them in a cold frame through their first winter. Plant them in their final sites in late spring.

Treat the edible fruit and its seeds as separate safety issues. PFAF warns that the seeds may contain hydrogen cyanide. This substance can cause severe poisoning in excess. That warning does not establish a safe amount to eat. PFAF lists no known medicinal uses or other uses. Its stated garden roles centre on woodland planting and sunny edges.