Halward's Silver Nippon spirea is somewhat smaller than the species. It produces abundant white flowers on a densely branched shrub with bluish-green foliage.

The genus Spiraea consists of small to medium sized flowering shrubs with a fine-textured twiggy mounding habit. The small simple leaves are generally lance-shaped and held close to the branch. Spring to early summer abundant blooms tend to be in white or pink tones, depending on the species and/or cultivar. While individual flowers are quite small, they occur in clusters of inflorescence that can be very showy.

Spireas are best used in groupings in a shrub or mixed border, where they are valued as tough, reliable and easy-care performers in northern climates. The Chicago Botanic Garden's collection includes nearly 100 varieties and 3,000 plants.