Grefsheim spirea (Spiraea × cinerea 'Grefsheim') is one of the earliest blooming spirea and is notable for its refined habit. Its arching branches are covered in small white flowers in the spring. It has been given the Award of Garden Merit by the Royal Horticultural Society and is one of the more widely planted spirea at the Chicago Botanic Garden.

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.

Spiraeas 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.