Black Locust (Robina pseudoacacia)
A fast growing tree maturing to 40-70’X40’ with an upright narrow and open canopy. Comfortable in a wide range of soils including salt and compacted clay this tree thrives along the Front Range and is very drought tolerant. Bland to catchy yellow in the fall and gorgeous yummy smelling flower clusters in the late spring. Short painful thorns at the base of leaves and deep dark furrowing bark appear like crusty ridges from the base to the twigs where they hardly smooth out. Propagates through legumes in pods and through an aggressive sprouting root system.
Prone to storm damage because of branch growth habits. Poor branch structure should be corrected through structural pruning every 3-5 years for the first 15-20 years of life. The seeds, bark and thorns are poisonous and should be kept from horses especially. If eaten by horses a vet check will likely be needed.
Some cankers are rare. Powdery mildew and some leaf fungi are common often yellowing the leaves mid summer and causing them to drop. Treatment is rarely warranted.
The Black Locust Borer is a serious problem pest causing major mechanical wounding to the trees structural integrity on young trees and major stress on older ones. Should be controlled if tree has value.
Several available. The most popular is the ‘Purple Lobe’ which has brilliant purple flower clusters that smell wonderful in the late spring. Again, it is very susceptible to the borer.
Traditionally used for many outdoor applications like fences, boats and nails because of its extreme hardness and resistance to rot. Also a huge favorite among honey bees who make a remarkable and sought after honey from the pollen of the Black Locust. Mistakenly named after the Mediterranean locust tree which has much religious historical significance.