Aesculus chinensis aka Chinese Horse Chestnut

Aesculus chinensis is a deciduous tree in the soapberry family. Its common names include Chinese horse chestnut and Chinese buckeye. Kew places its native range from central and southern China into northern Laos. Other sources focus on its range in northern China. It grows in woods, thickets, ravines, and on slopes. Records also place it beside roads and in mountain habitats.

The tree forms a broad, rounded crown with spreading branches. Garden trees often reach 30–40 feet (9–12.2 metres) tall. RHS gives a height of 49 feet (15 metres). Some trees reach 70 feet (21 metres), beyond the usual garden range. Reported spreads range from 13–40 feet (4–12.2 metres). The green leaves sit opposite each other on long stalks. Each palmate leaf has five to seven leaflets. These reach 3–10 inches long and have fine, toothed edges. Their undersides lack hairs except along some veins. The tree sheds its leaves each year.

White flowers form upright clusters at the ends of branches. These panicles reach about 16 inches long. Each flower has four petals, sometimes marked yellow or red. The stamens extend beyond the petals. Missouri Botanical Garden gives May to June as flowering time. RHS places flowering in midsummer, so timing may vary. Round fruit capsules follow the flowers and add seasonal interest. Their rough skins have no spines. Each ripe capsule splits and releases one or two dark brown seeds.

Grow this tree in deep, rich soil with good drainage. It needs steady moisture and does poorly in dry soil. Loam suits it well, though RHS lists several soil types. It accepts acid, neutral, or alkaline soil. Full sun suits it, and it also tolerates partial shade. Sources list USDA zones 5–7 and UK hardiness H7. Use it as a specimen, shade tree, or street tree. Its broad crown can also form a woodland garden canopy. RHS gives a maturity period of 20–50 years. Scale insects and leaf-mining moths may attack it. Coral spot, canker, and leaf spot are possible diseases.

The seeds are poisonous and contain saponins. PFAF reports food use only after processing to remove toxins. This does not make raw seeds safe to eat. It also records traditional medicinal uses for the seeds. Seed saponins can serve as a soap substitute.