Culture
Easily grown in average, medium moisture, well-drained soils in full sun. Tolerates a wide range of soils. Remove faded flower clusters as practicable (light shearing is an option) to encourage additional bloom. Flowers on new wood, so prune in late winter to early spring if needed.
Noteworthy Characteristics
Spiraea betulifolia, commonly called birchleaf spirea, is native to Japan and eastern Asia. It is a dwarf shrub that typically matures as a dense rounded mound of foliage to 3' tall and as wide. Birch-like, round to egg-shaped leaves (to 2" long) have toothed margins. White flowers in clusters (corymbs) cover the foliage in mid-summer. Flowers are attractive to butterflies. Foliage turns quality shades of orange, red and purple in autumn. Varieties of this species include Spiraea betulifolia var. corymbosa (shinyleaf meadowsweet) which is native to the eastern U.S. (Pennsylvania south to Alabama and Georgia) and Spiraea betulifolia var. lucida (shinyleaf spirea) which is native to western North America (British Columbia to Saskatchewan south to Oregon, Wyoming and Minnesota).
Genus name comes from the Greek word speira meaning wreath in reference to the showy flower clusters seen on most shrubs in the genus.
Specific epithet comes from the birch genus (Betula) and leaf (folia) in obvious reference to the leaf shape.
‘Tor’ typically grows 2-3’ tall in a dense, compact, rounded mound. Tiny white flowers in small flattened clusters (corymbs) cover the foliage in late spring. Birch-like, dark green leaves (to 1.5” long) are oval and sharpely toothed. Foliage turns quality shades of orange, red and purple in autumn. Flowers are attractive to butterflies. Cultivar name presumably comes from the Gaelic word torr meaning hill or mound, in reference to the plant habit.
Problems
No serious insect or disease problems. Susceptible to many of the diseases and insects that attract other rose family members, including leaf spot, fire blight, powdery mildew, root rot, aphids, leaf roller and scale.
Uses
Specimen or group for rock gardens. Mass or group in shrub borders. Low hedge for paths and walkways. Incorporates well into foundation plantings. Butterfly garden.