Black locust trees now displaying showy blossoms

The trees you now see throughout the county with the showy white flowers are probably black locust trees. Black locust (Robinia pseudoacacia) is a medium-sized tree with a single small leaf and thorns along the twigs and smaller branches. The bark of the locust tree is deeply furrowed with a grayish orange color.

Black locust has showy white flowers borne in clusters with a pleasant aroma much like orange blossoms. The bloom begins in late May and remains for a few weeks. Bees and hummingbirds are the main pollinators of this plant. The seed of the locust is borne in a pod and this develops in late summer.

Black locust is part of the legume family and it enriches the soil by “fixing” nitrogen, taking it from the air and secreting it in the soil where it can be used by other plants. Black locust needs full sunlight throughout its life. This tree is one of the first trees to colonize an abandoned field and is an integral part of old field and young forest associations oftentimes growing alongside cedar, Virginia pine, tulip poplar, black cherry, elm, persimmon, and red maple.

Locust is a fast-growing tree with a shallow root system; because it is prone to wind throw, it makes a poor choice as a landscape tree. Locust does not live long, typically about 50 years. The locust is a very hardy tree and is often planted in strip mine reclamation projects or as a nurse tree for longer- lived trees like walnut and oak during reforestation projects.

Locust wood is heavy, hard, and rot-resistant; thus, it is a favorite wood for fence posts and firewood. Locust honey is another locally important product derived from this tree. Every year black locust leaves are attacked by locust leaf miner in late summer. This insect eats the inner “green” tissue of a leaf leaving the leaf with a dull brown color. Despite this damage the tough locust tree bounces back from this damage sending out healthy green leaves the following spring.

Nature Notes for 6/9/2013