James H. Schutte
RUBUS 'Hull Thornless'
Plant Common Name
This entry has yet to be reviewed and approved by L2G editors.
Comprising some 250 species of small to medium-sized, often prickly shrubs, this cosmopolitan genus includes the raspberries, blackberries, and many other valuable culinary and ornamental plants.
Most Rubus bear lobed or divided, deciduous or evergreen leaves on arching, creeping, climbing, or upright stems. The leaves are often maple-shaped (if lobed) or pinnate (if divided). A silver-gray bloom covers the stems of some brambles, giving them a whitewashed appearance. Plants bear large to inconspicuous five-petaled flowers, which at their showiest resemble single roses. The white, pink, or purple blooms often have a central ruff of yellow stamens. Bees and butterflies visit the flowers. The red, black, yellow, or white "berries" that follow the blooms are actually aggregate fruits containing five or more fused fleshy fruits known as drupelets.
Several Rubus are important culinary plants. Raspberry, R. idaeus, has given rise to numerous selections and hybrids grown for their summer to fall bounty of succulent red or yellow fruits. Commercial blackberries derive from several species including the North American R. allegheniensis. R. occidentalis is the chief parent of black raspberry cultivars, which bear smaller, dome-shaped fruits. Other Rubus grown for their fruits include loganberry, a hybrid of R. idaeus and the California native R. ursinus.
Many Rubus are first-rate ornamental plants. The flowers of some brambles - such as R. deliciosus and its hybrid 'Benenden' - rival those of any rose. In addition to attractive blooms, R. odoratus, R. parviflorus, and several other North American species feature large downy maple-like leaves. The foliage of some brambles (including R. crataegifolius) turns brilliant hues in fall. Creeping evergreens such as R. tricolor make excellent (if sometimes invasive) ground covers. And the so-called "ghost brambles" such as R. cockburnianus enliven the winter garden with their white stems.
Most Rubus require little special care, with many doing well in poor soils or partial to full shade. Those grown for their "berries" prefer ample sun and well-drained soil, producing most heavily if their bearing canes are removed following fruiting. Likewise, old ghost bramble stems should be cut to the ground in spring or after bloom to force colorful new growth. Some Rubus species are potentially invasive.