Gymnocladus chinensis

Gymnocladus chinensis is a deciduous tree in the bean family, Fabaceae. Its common names include Chinese coffee tree and soap tree. Its native range runs from Arunachal Pradesh to southern China. It grows on plains and foothills in a subtropical climate. It grows slowly and forms an upright trunk with a rounded or uneven crown. Garden trees reach 15–30 feet (4.6–9.1 metres) tall. Their spread reaches about 20–30 feet (6.1–9.1 metres).

The large leaves are bipinnate and grow alternately along the stems. New leaves open purple, then turn green as they mature. In autumn, they turn bright yellow before they fall. The oval leaflets have smooth edges and fine, silky hairs on both sides. Young stems mix purple and green tones. Older bark turns grey-brown, with clear pale lenticels on its surface. These marks stand out against the darker bark.

Small flowers hang in racemes during spring. They are pale yellow to white, with a purple tint. Male and female flowers grow on separate trees. Both sexes must be present for fruit to form. The fruits are legumes that reach 0.46–0.83 feet (0.14–0.25 metres) long. They mature in autumn. Warm summers help the tree flower well. It seldom flowers in Britain, where summer heat may be too low.

Grow this tree in full sun, sheltered from cold winds. Deep, rich soil that holds moisture but drains well suits it. It also tolerates poor soil and fixes nitrogen through root bacteria. Cold tolerance reports differ, so local conditions matter. NC State lists USDA zones 7–11, but notes uncertainty at the colder end. Plants For A Future gives a lower limit near 23°F (−5°C). That source restricts British planting to the mildest areas. Its open crown gives light shade in a woodland garden. It also serves as a small shade or understory tree.

Few major pest or disease problems are reported. Webworms and scale can still occur. The fruit contains saponins and has been used to make soap. The hard, durable wood serves in cabinet work. Sources report cooked seeds as food, but raw seeds pose serious risks. NC State warns that leaves, seeds, fruit pulp, and bark are poisonous. Raw seeds can cause vomiting, nausea, and fatal poisoning. Keep fallen leaves and seeds away from children, pets, and grazing animals. Reports of cooked use do not establish a safe home preparation method.