Purple Robe Locust 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. Leaves are dull, dark blue-green and pinnately compounded. Fall color is yellow. Flowers are dark rose-pink, in dense clusters, May to June. Lonf, slender pods follow flowers and persist into autumn. Bark is warm gray and furrowed; branches have spines.
Hardy to zone 3, this locust prefers full sun, is tolerant of most soils and fixes nitrogen. It is not a tree for stressful planting situations in dry climates. Provide adequate water during establishment and moderate watering thereafter. Borers can be problematic following stress. Should be pruned in late summer to avoid "bleeding."