Culture
Grow in average, medium moisture, well-drained soil in full sun. Pruning strategy depends on what features of plant are to be emphasized: prune immediately after flowering or fruiting for best flowering and fruiting, or prune in late winter for best stem color and foliage.
Noteworthy Characteristics
Rubus biflorus is an upright, somewhat climbing, deciduous shrub with cane-like stems which typically grows 3-6' tall (to 12' if given support and not pruned). First year canes are covered with a chalky white waxy coating which is quite striking in winter after the foliage has dropped, and this shrub is usually ornamentally grown for this purpose. Fragrant, white, 3/4" wide flowers appear in small clusters of 5-8 at the stem ends in spring. Flowers give way to yellow, 3/4" diameter fruits (raspberries) which are edible. Flowers and fruits will be absent if canes are pruned to ground in late winter. Compound dark green leaves (3-5 leaflets each) are 5-8" long and white beneath.
Genus name is the Latin name for brambles (blackberry and raspberry).
Specific epithet means twin-flowered.
Problems
No serious insect or disease problems. Aggressive, suckering habit.
Uses
Chalky white stems in winter are quite attractive in somewhat the same way as the red and yellow stems of some willows and dogwoods (e.g., see Salix and Cornus). Attractive in front of evergreens. Naturalized areas. Shrub borders.