Sedum japonicum aka Tokyo Sun

Sedum japonicum, or Japanese stonecrop, belongs to the Crassulaceae family. Its native range runs from southeastern China into temperate eastern Asia. Records include China, Japan, and Taiwan. It is not native to Britain or Ireland. In Japan, it grows among rocks in thin woods. It also occurs on sunny slopes in the foothills. These records cover central and southern parts of Japan.

This small evergreen plant reaches about 0.7 feet [0.2 metres] tall. PFAF describes it as a perennial; Kew calls it a succulent subshrub. It keeps its leaves through the year. PFAF notes that the species varies in form. Its yellow flowers appear from July to August. Each flower has both male and female organs. Insects pollinate the flowers, and the plant is self-fertile. Seeds ripen from August to September, after the flowering season.

Give this plant a sunny site with soil that drains well. PFAF states that it cannot grow in shade. It accepts sandy, loamy, and clay soils, but prefers fertile ground. Suitable soil ranges from mildly acid to mildly alkaline. It can grow in either dry or moist soil. Once established, it can cope with drought. PFAF reports cold tolerance down to about −15°C. Good drainage remains part of its stated needs across soil types.

Garden uses include beds, sunny woodland edges, and planting within walls. PFAF lists east-, south-, and west-facing walls as possible sites. These uses suit a small plant that needs sun. Gardeners can raise new plants from seed or by division. Sow seed on the surface in spring, under glass. Use well-drained soil and keep the seedbed from drying out. Divide plants during the growing season, preferably in spring or early summer. Plant large divisions straight into their final sites. Smaller divisions benefit from time in pots before planting out.

PFAF records both leaves and stems as edible, raw or cooked. However, it also states that they need thorough boiling. It warns that eating large amounts can upset the stomach. This caution matters despite its description of the plant as non-poisonous. Its food-use score is only one out of five. PFAF lists no known medicinal uses or other uses. It also records no weed potential for this species.