Hackberry Leaf Facts

Leaf Description

• Oval, a common hackberry leaf reaches a length of 2 to 5 inches and a width of 1 to 2 1/2 inches at maturity. It tends to be rough on top with a smooth or slightly hairy underside near the veins, and it has serrated edges. The petiole, or stalk that joins a joins a leaf to a stem, averages 2/3 inch long. The unequal leaf base slants, with one side larger, wider or rounder than the other side, a feature known as an oblique leaf base.

Close Relatives

• Leaf texture and shape are used to identify relatives of the common hackberry tree. The varieties include small hackberry (Celtis occidentalis pumila) and dwarf hackberry (Celtis tenuifolia). In addition to being smaller in height than common hackberry, those trees produce leaves that are smaller than common hackberry leaves, and their leaves have no teeth or just a few teeth along their edges.

Beneficial Uses

• Common hackberry leaves are considered allelopathic, meaning they impede plant growth, making them an excellent choice to use as mulch for pathways or any other location to discourage weed growth. The leaves also are a favorite food of several kinds of butterfly caterpillars, such as the tawny emperor that lays eggs in groups of 200 to 500 on the leaves. Other animals that feed on common hackberry leaves include slider turtles, fox squirrels and deer. Scientists with the National Center for Atmospheric Research include hackberry and its leaves as one of the most beneficial tree species for removing pollutants from air.

Pests and Diseases

• Several insect species lay eggs on common hackberry's leaves, causing pouches or nipple galls to form on the leaves' lower surface. These galls can disfigure leaves but don't cause serious damage. Other pathogens that attack hackberry leaves include leaf-spot fungus, which results in blotchy patches, and powdery mildew, which coats the leaves with a white powder.