Black Locust (Robinia pseudoacacia)-Hort Answers - University of Illinois Extension
University of Illinois Extension

University of Illinois Extension

Hort Answers

Tree

Black Locust
Robinia pseudoacacia

Black Locust form
Black Locust form
 
Features
Fragrant clusters of white flowers in late spring. 
 
Culture
Full sun; prefers moist, well-drained soil, but tolerates dryness; tolerant of alkaline soil. 
 
Cultivars
 
 
Mature Height
40-60 Feet
 
Size
Medium
Large
 
 
Mature Form
Narrow oblong to irregular crown; can form thickets by suckering roots. 
 
Native To:
United States 
 
USDA Hardiness Zone
4 - 8 
 
Soil Conditions
Dry
Moist, Well-Drained
 
 
Tolerance
Alkaline Soil
Dry Sites
Salt
Wind
 
 
Exposure/Light Requirements
Full Sun
 
 
Uses
Shade
 
 
Foliage Color
Green
 
 
Fall Foliage Color
Green
 
 
Pests and Problems

Environmental Damage

Fungal Disease

Insect Damage


Additional pests and problems that may affect this plant:

Locust borers are a serious problem. Weak-wooded branches may be damaged by wind.
 
Additional Notes
Thicket-forming habit and damage by borers limits the usefulness of this species in the home landscape.

 

 
Related Resources
Home, Yard & Garden Pest Guide
Illinois Commercial Landscape and Turfgrass Pest Management Handbook
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic