Spiraea betulifolia Tor

The Spiraea betulifolia 'Tor', or Birch-leaved spirea, is a small deciduous compact shrub or bush with massive spring flowering in corymbs of small white flowers that delight butterflies. Its foliage turns flamboyant colours in autumn. Undemanding, it will find its place in all gardens, and will adapt to all climates.

The 'Tor' Birch-leaved spirea belongs to the Rosaceae family. It is a mutation of the Birch-leaved spirea native to eastern Siberia, Japan, and Sakhalin Island. The growth of this shrub is slow and its adult size will not exceed 80 cm (31.5 in) in all directions.
The Spiraea betulifolia 'Tor' is a small deciduous shrub with an upright and compact habit. The flowering, which takes place in May-June, is so abundant that the shrub disappears under a white snow blanket. The flowers, 0.50 cm (0.2 in) in size, are grouped in corymbs of 3.7 cm (1.5 in) that are very visited by butterflies. The foliage emerges from purple buds that open into small leaves measuring 2 to 4 cm (0.8 - 1.6 in), similar to those of the dwarf birch. Oval and toothed, they are dark green with a hint of blue. This small shrub ignites in autumn, with its foliage taking on shades of gold, copper, orange, and purple to violet depending on the nature of the soil.

Plant this spirea in moist to wet, humus-rich, well-drained, neutral or acidic soil. This shrub will thrive in partial shade but preferably in full sun. The autumn colours will be richer and more pronounced in neutral to acidic soil. To encourage a second flowering, remove faded flowers. Prune after flowering to maintain a compact habit.

The Spiraea betulifolia 'Tor' is ideal as a ground cover, in shrub borders along pathways, or even as a standalone specimen in rock gardens. You can place it at the forefront of a countryside hedge, accompanied in its autumnal blaze by sacred bamboo (Nandina domestica) and its shorter cousin Nandina 'Fire Power', Imperata cylindica 'Red Baron', or the hazy Eragrostis spectabilis. Create a highly contrasting combination with the foliage of Pulmonaria longiflora 'Diana Clare' and Carex testacea.