Spiraea nipponica, or Snowmound Spiraea, is a drought-tolerant, flowering, deciduous shrub growing rapidly to its full size. For most Spiraea species, the height can range from 5 to 8 feet high and an equal spread; however, Snowmound tends to be a bit smaller with a 2 to 4 foot height. When young it is a slender, slightly arching, shrub, but becomes denser and mounded with age. It grows well in average, medium moisture, well-drained soils in full sun to bring out the best blossoms. However, it will also thrive with light afternoon shade if sited in a place with hot summer climates. It tolerates a wide range of soils, including clay.

The plant blooms in late spring, which is later than other white-flowered spiraeas, and produces a frothy shower of clustered, small, white flowers that cover the limbs like a mound of snow. The blue-green leaves are shaped as narrow triangles with an acute angle toward the base. Flowers and leaves all appear on the same side of the arching branches. Flowers are attractive to butterflies.