Rubus deliciosus aka Rocky Mountain Raspberry

Rubus deliciosus is known as Rocky Mountain flowering raspberry or showy white-flowered bramble. It belongs to the rose family, Rosaceae. Its native range runs from the west-central United States into northern Mexico. It grows among scrub and on rocky mountain slopes. This is a plant of temperate regions. It is not native to Britain or Ireland.

This deciduous shrub grows at a moderate rate. It can reach about 10 feet [3 metres] tall. Its stems lack prickles and remain alive for several years. That makes its pruning needs different from those of ordinary raspberries. Remove dead stems rather than cutting it back like a fruiting raspberry. Its thornless stems and scented flowers give it value as an ornamental shrub. The supplied species evidence gives no further leaf or bark details.

Flowers appear from May to June and have a sweet scent. Each flower has both male and female parts. Bees pollinate them, and the seeds ripen in July. The rounded fruit measures about half an inch across. You can eat it raw or cooked. Reports differ on how good it tastes. Some describe a pleasing flavour; others find it dry and bland. The fruit has many seeds and little flesh. It also yields a dye in purple to dull blue shades.

Grow this shrub in sun and soil that drains well. A good loam suits it, though it accepts sand and clay. It tolerates mildly acid, neutral, and mildly alkaline soils. It prefers moist ground rather than a shaded site. Plants For A Future lists USDA zones 4–8. It also reports cold tolerance near −20°C. These points support its use in cold-climate gardens. The same source describes it as easy to grow.

Seed, cuttings, and division offer ways to raise new plants. Sow fresh seed in early autumn in a cold frame. Stored seed needs a cold treatment before sowing. Take half-ripe cuttings in July or August. Divide plants in early spring or before autumn leaf fall. Plants For A Future reports no known hazards or medicinal uses. It also records no weed potential. Its clearest garden roles are ornamental planting and providing edible fruit.