Castanopsis cuspidata aka Japanese Chinquapin

Castanopsis cuspidata is an evergreen tree in the beech family, Fagaceae. Its common name is Japanese chinquapin. Kew places its native range in central and southern Japan. Plants For A Future gives a wider East Asian distribution. This includes parts of China, Japan, South Korea, and Taiwan. Kew links the species with a subtropical climate. Reported habitats include woods and ravines, with some sites near the sea.

The tree can reach about 82 feet (25 metres) tall. Its spread can reach about 33 feet (10 metres). It keeps its leaves throughout the year. In gardens, it can form the canopy of a woodland planting. British conditions can limit its growth and final size. Plants For A Future reports success around London and southwest England. London trees do not reach the full size given for the species.

Each tree bears separate male and female flowers. The flowers form catkins with a scent some people find unpleasant. Plants For A Future compares the smell with hawthorn flowers. The scent draws midges, which help pollinate the flowers. Wind also plays a role in pollination. The nuts contain edible seeds that people eat after cooking. Their cotyledons, the seed leaves within each nut, can be boiled or roasted.

Give this tree shelter and a site with partial shade. It prefers moist soil and a deep loam. It also grows in heavier clay soils. Plants For A Future lists mildly acidic and neutral soils as suitable. Its cultivation notes call for soil free of lime. The source gives USDA hardiness zones 6–9. Yet surviving cold does not mean the tree will thrive. It favours warm continental conditions over Britain's maritime climate.

Fresh seed offers a way to raise new trees. Sow ripe seed in a cold frame without letting it dry. The seed needs cold stratification and loses viability within a short time. Cool, moist storage can preserve it for a few months. Soak stored seed in warm water for 24–48 hours before sowing. Germination can take one to three months at 59°F (15°C). Plants For A Future lists no known hazards or medicinal uses. It also reports no weed potential.