Hardy to zone 3, this locust prefers full sun, is tolerant of most soils and fixes nitrogen. Purple Robe Locust(Robinia pseudoacacia 'Purple Robe') is a medium-sized upright tree, growing 40 feet in height with a compact, rounded form. The trunk is long and straight with an interesting branching pattern. Borers can be problematic following stress. Should be pruned in late summer to avoid "bleeding." The flowers of the Purple Robe Locust are showy, pea-like and occur in pendulous clusters 4 to 8 inches long. The Purple Robe Locust flowers in late spring and continuing into the summer, Purple Robe Locust's long drooping fragrant flowers look like a wisteria's flowers.
• The foliage of the Purple Robe Locust consists of alternate, pinnately compound leaves. These leaves are 6 to 14 inches long and have 7 to 9 elliptic-shaped leaflets.The spectacular flowering clusters of a purple-pink color hang like clusters of grapes practically covering the entire tree. This amazing flowering tree grows new leaves of a metallic bronze-red color that mature to a bright green color.
Purple Robe Locust Flowering Tree