A black locust G. Lumis	The leaf and flower of a black locust G. Lumis	The deeply furrowed bark of a black locust G. Lumis

Scientific Name: Robinia pseudoacacia

Hardiness Zones: 5 to 8 
Height: 40 ft
Spread: 25 ft
Form: oval 
Type: deciduous tree 
Annual Growth Rate: more than 18 inches 
Flowers: White 

Comments
Black Locust is hard wooded, grows best in a sunny location and tolerates any soil that isn't swampy.  This hardy tree is a legume and has a suckering root system that forms thickets if not controlled. The fragrant, white flowers appear after the leaves and are borne in drooping clusters. The fruit is a brown pod and the bark is coarse and fissured. 

Cultivars 
'Bessoniana' - A thornless cultivar with a compact oval form that will be 30 feet tall and 20 feet wide. 

'Frisia' - The tree has bright yellow summer foliage color. 

'Inermis' - A rounded tree with thornless branches. 'Lacy Lady' (Twisty Baby TM) - This 8-foot tall plant has crooked stems and curled foliage. 

'Purple Robe' - The new growth is purplish and the flowers are dark purple. 

'Pyramidalis' - This cultivar is tall, narrow, and spineless. The plant will be 40 feet tall but only 15 feet wide. 

'Umbraculifera' (Globe Locust) - A dense, globe-shaped head on a tree only 12 feet tall and wide, rarely flowers. 

Text courtesy Michigan State University Extension