Overview
Rubus parviflorus is thimbleberry (western thimbleberry), an upright deciduous shrub growing 3-6 feet (0.9-1.8 m) tall and 3-6 feet (0.9-1.8 m) wide with no thorns or prickles — one of the few thornless Rubus species. Large simple palmately 3-5 lobed (maple-shaped) soft velvety leaves 4-8 inches (10-20 cm) — unusual for Rubus (most species have compound leaves). White 5-petaled flowers 1-2 inches (2.5-5 cm) with papery crinkled petals in terminal clusters of 3-7 in May-June. Edible red thimble-shaped raspberries 0.5-0.75 inch (1.3-2 cm) ripen July-August — soft, fragile, and difficult to transport. The fruit separates cleanly from the receptacle like a raspberry, forming a hollow thimble shape. In Rosaceae. Native to western North America — Alaska to California and east to the Great Lakes. Spreads by rhizomes to form colonies — this rhizomatous spread is the primary maintenance limitation. The colony can expand into areas where other plants are growing. Deer browse the foliage. Not drought-tolerant — requires consistent moisture. The fruit is produced in small quantities and does not ship well. Non-toxic. Zones 3-8. Part shade to full shade. Growth rate is moderate to fast.
Native Range
Native to western North America — from Alaska to California and east through the Rocky Mountains to the Great Lakes region. Found in moist forest openings, stream banks, avalanche chutes, and disturbed areas.Suggested Uses
Grown in native plant gardens, woodland understories, and restoration plantings spaced 3-6 feet (0.9-1.8 m). Thornless. Edible fruit (does not ship well). Large maple-shaped leaves. Spreads by rhizomes. Native to western North America. Non-toxic. Zones 3-8.How to Identify
Appearance
Size & Dimensions
Height3' - 6'
Width/Spread3' - 6'
Reaches mature size in approximately 3 years
Bloom Information
Late spring to early summer (May-June). White 5-petaled flowers 1-2 inches (2.5-5 cm) with papery crinkled petals in clusters of 3-7. 4 weeks of bloom. Bee- and butterfly-visited. Red thimble-shaped raspberries ripen July-August.Detailed Descriptions
Flower Description
White, 5-petaled, 1-2 inches (2.5-5 cm) across, in terminal clusters of 3-7; papery crinkled petalsFoliage Description
Medium to bright green, simple (not compound — unusual for Rubus), large, palmately 3-5 lobed (maple-shaped), 4-8 inches (10-20 cm) across, soft and velvety; turns yellow in fallGrowing Conditions
Sun Requirements
Requires 2-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Part shade to full shade (2-6 hours). Moist soil pH 5.0-7.0. Not drought-tolerant. Spreads by rhizomes — contain or allow to colonize. No thorns. Deer browse. Prune in late winter (February-March). Non-toxic. Zones 3-8.Pruning
Prune in late winter (February-March). Remove spent second-year canes at ground level after fruiting. Thin the colony by removing excess rhizome shoots to control spread. The thornless stems make handling easy.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring