Gleditsia japonica aka East Asian Honey Locust

Gleditsia japonica, or Japanese locust, is a deciduous tree. It belongs to the pea family, Fabaceae. PFAF places its native range in Japan, in eastern Asia. Its wider distribution includes parts of China and Korea. It is not native to Britain or Ireland. Trees grow at a moderate rate. They reach about 65 feet [20 metres] tall. Their spread can reach about 39 feet [12 metres]. Allow space for this large tree to develop.

The canopy is light rather than dense. Leaves emerge late in spring and fall early in autumn. This short leaf season helps explain its woodland garden value. PFAF recommends it as a canopy tree for that setting. Insects pollinate its flowers, which contain male and female organs. The tree bears pods that hold its seeds. Trees at Kew have produced pods with fertile seeds. They have fruited in both hot and cool summers. In Japan, people grow the tree for its pods.

Choose a sunny site with soil that drains well. The tree does not grow well in shade. Loam suits it, but it also grows in sand and clay. It accepts mildly acid, neutral, and mildly alkaline soils. It can grow in dry or moist ground. Once established, it can withstand drought. It also tolerates air pollution. PFAF lists USDA hardiness zones 5–9. Young trees can suffer from cold and need winter protection. Older trees are reported to be fully hardy in Britain. Southern Britain offers better conditions for young growth.

Seeds and young leaves have recorded food uses after cooking. Seed preparation involves roasting, removing the husk, soaking, and boiling. The cooked seeds may then be served with sugar. Young leaves have served as a famine food. PFAF lists no known hazards for this species. That does not establish safety for every person or pet. The source also records traditional medicinal uses for coughs and skin complaints. These reports do not establish safe or effective home treatments.

Pod pulp provides a source of soap. Another report identifies the seeds as the soap source. The wood is strong, durable, and coarse-grained. To raise trees, soak seeds in warm water before sowing. Protect young plants during their first few winters outdoors.