Robinia hispida
Midwest Noxious Weed: Do Not Plant
Common Name: bristly locust 
Type: Deciduous shrub
Family: Fabaceae
Native Range: Central and eastern United States
Zone: 5 to 8
Height: 2.00 to 10.00 feet
Spread: 5.00 to 15.00 feet
Bloom Time: May
Bloom Description: Rosy pink to purplish-red
Sun: Full sun
Water: Dry to medium
Maintenance: Medium
Suggested Use: Hedge
Flower: Showy
Fruit: Showy
Tolerate: Deer, Drought, Erosion, Dry Soil, Shallow-Rocky Soil
This plant is listed as a noxious weed in one or more Midwestern states outside Missouri and should not be moved or grown under conditions that would involve danger of dissemination.

Culture

Grow in average, dry to medium moisture, well-drained soil in full sun. Prefers organically rich soils, but tolerates poor, dry soils.

Noteworthy Characteristics

Robinia hispida, commonly called rose locust or rose acacia, is a showy-flowering, deciduous shrub which typically grows variably from 2-10' tall. In the wild, it can aggressively spread by suckering, but in cultivation, nurseries often graft it to the roots of R. pseudoacacia (black locust) which results in a much less aggressive plant. May be trained or topgrafted to form a small tree. Rose to pale purple flowers appear in 2-4" long, pendulous racemes in May. Compound pinnate, medium to dark green foliage (7-15 leaflets). Flowers are infrequently followed by bristly, purple seed pods (to 3" long). Branches, petioles, flower stalks and fruits are hispid (stiffly hairy) as the species name suggests, thus giving rise to another common name of bristly locust. Steyermark lists this southeastern U.S. native as a garden escape in Platte and Howell counties in Missouri.

Genus name honors Jean Robin (1550-1629), of Paris, gardener to Henri IV and Louis XIII of France, who received new plants from Canada.

Specific epithet means bristly or stiffly hairy.

Problems

Borers can be a significant problem. Leaf spot, powdery mildew, canker, scale and leaf miner are lesser potential problems. Branches are susceptible to damage from heavy winter snows and ice storms.

Garden Uses

Excellent flowers and foliage. Specimen or screen. Good plant for stabilizing embankments and slopes and for planting in poor, dry soils. Interesting informal hedge.