introduced from the southern United States as an ornamental tree and as a source of hard, rot-resistant wood
still available from nurseries
most abundant in southern Ontario but occurs east to Nova Scotia as well as in British Columbia
Biology
a medium-sized tree (up to 25 m or 80 ft tall) with long compound leaves
belongs to the Pea family
like many other species in the Pea family, it has nitrogen-fixing bacteria in its roots enabling the tree to grow vigorously in poor soil
reproduces by root suckers to form dense clones of interconnected trees
in spring the trees produce large, drooping clusters of fragrant, white flowers
large, hanging, multi-seeded pods form in the summer and remain on the tree until the next year
seeds rarely germinate although they are produced in large numbers
branches contain pairs of short, sharp spines
prefers open areas with well-drained soil and lots of light but tolerates a wide range of growing conditions
stumps will re-sprout vigorously if cut
Impact on Trees
may grow in dense stands in open woodland, forest openings, and forest edges
suppresses native tree seedlings due to shade
enables invasion by other non-native species by enriching the soil with nitrogen
What can be done to control this tree killer?
cutting or girdling stems followed by herbicide application to the cut stems or later removal of sprouts that develop after cutting
several years of control may be needed since stumps can resprout one or more years after treatment