The alpine Japanese spirea is a miniature cultivar that grows to a mound of two feet, spreading to three feet, with tiny densely set leaves. It features flat clusters of rose-pink flowers.

The Spiraea japonica species includes the greatest range of cultivars available to the home gardener within the Spiraea genus. They all have a compact mounding habit in sizes ranging from 18" to 5' that makes them useful in borders and smaller spaces. The cultivars also offer foliage coloration ranging from green to yellow/gold and bloom coloration ranging from pale pink to dark pinks that are almost red or purple. These versatile shrubs bloom on new wood and may benefit from rejuvenation pruning in March prior to the emergence of new growth. Most offer a secondary bloom after the initial display.

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.