Spiraea blumei aka Montane Spiraea

Spiraea blumei, or Blume spirea, is a deciduous shrub. It belongs to the rose family, Rosaceae. Its native range spans China, Korea, and central and southern Japan. It grows in temperate parts of East Asia. Wild plants occur in thickets, ravines, and mixed woods. They also grow on sunny slopes and along roadsides. Records place these habitats at 1,640–6,560 feet [500–2,000 metres] above sea level.

This shrub grows upright and reaches about 5 feet [1.5 metres]. It loses its leaves for winter. White flowers open in May and June. Each flower has both male and female organs. Insects pollinate the flowers, and the plant draws butterflies. Seeds ripen from August through October, after the flowering season. The species varies in form. Garden plants can be confused with Spiraea trilobata. It also crosses freely with other members of its genus. This can make the identity of garden plants less clear.

For cultivation, it prefers full sun and soil that holds moisture. Plants For A Future also records tolerance of light shade. Chicago Botanic Garden lists sun, partial shade, and full shade. Full sun is therefore the clearest choice among its stated preferences. It accepts sandy soil, loam, and clay, but prefers good loam. It also tolerates mildly acid, neutral, and mildly alkaline soils. Keep its preference for moist ground in mind when choosing a site. Chicago Botanic Garden lists moderate water needs and USDA zones 3–8.

Garden uses include beds, borders, and the edges of woodland plantings. Its upright form and white flowers suit these settings. The flowers add spring and early summer interest. Butterfly visits add wildlife value during the bloom season. Plants For A Future lists both sunny and shaded woodland edges as sites. It does not flag this species as weedy. The supplied accounts name no species-specific pests or diseases.

The leaves have a recorded use as a tea substitute. Plants For A Future gives the plant a low edible-use score. That source reports no known hazards, but this is not a full safety assessment. It lists no known medicinal use. It also records no other uses beyond those described. Growers can raise plants from seed or take wood cuttings. The source gives summer and autumn cutting options.