In poor, dry sites, growth is so stunted that the plant appears as a shrub. Early growth of hackberry varies greatly within its range. Staminate flowers appear singly or in clusters of two to three at the base of a short, green branch. Hackberry fruit is a round drupe with a thin, sweet, edible pulp enclosing a bony, cream-colored nutlet.
Hackberry is host to a large number of insects and diseases, most of which cause no serious damage.
Four gall-producing insects attack this tree, and the entire crown may be defoliated by the spiny elm caterpillar or the hackberry butterfly caterpillar. The hackberry engraver beetle attacks mostly dead or dying branches, but has been reported to attack living sapwood as well, causing the tree to die. Many ecotypes of this variable species are known to occur. Varieties are distinguished by such morphological charcteristics as growth form, height, leaf size and margin, and fruit shape and color. Hackberry regenerates primarily through sexual reproduction.