Decorative deciduous shrubs with thin twigs and white or rose-redin round or elongated clusters.
Excellent in the shrub border, in the bend of a garden path, but finest of all as a free-standing specimen shrub. Will tolerate a certain amount of shade, but in full sun flowering will be more profuse. Summer-flowering species may be cut down almost to ground level in spring.
Spring-are thinned out a little every year after flowering has ceased, in order to retain their compact shape.
Not very exacting as to soil; standard garden soil will do.
Propagation From suckers, by, or from winter .
albiflora: Height 50 cm; white flowers in summer months.
Spiraea arcuata: Height to 2 m; white flowers in hairy, spherical umbels in late spring and early summer. Spiraea X arguta: Height to 2.5 m, clusters of white flowers on gracefully arching thin twigs in mid spring; one of the finest species.
Spiraea bullata: Height to 40 cm; racemes of deep-pink flowers in early to mid summer. Small dark-green curled.
Spiraea bumalda hybrids: Height to 1 m; clusters of flowers, usually red, in mid summer to early autumn. The twigs are streaky, the bark frequently peels off. ‘Anthony Waterer’, which has violet red flower clusters, is one of the best known strains. Often produces a number of white. Must be cut right down every spring. Spiraea japonica: Height just over 1 m; rose-red flowers in dense racemes in mid to late summer. ‘Little Princess’ does not grow beyond 50 cm; ‘Macrophylla’ has large, lumpy leaves and fairly small flowers. Cut right down in spring. Spiraea nipponica: Height to 1.5 m; white flowers in dome-shaped clusters in late spring and early summer. Slightly arching twigs.
Spiraea thunbergii: Height to 2 m; white flowers in sparse, sessile clusters on somewhat arching twigs. Very attractive, but in severe winters the tips of the twigs may freeze. Spiraea X vanhouttei: Height 1.5 m; white flowers in flat umbels in late spring and early summer. One of the finest species.