In youth, Hackberry’s branching habit is very unruly, numerous branches with leaders everywhere! When the tree reaches 3 inches in caliper, it looks very much like an elm. Very adaptable tree, growing in wet and dry soils in full sun. Does well as a street t ... ree. The birds relish the purplish-black fruit. Hackberry is susceptible to nipple gall and witches broom, with nipple gall being the most prevalent. The gall and the tree get along just fine; it is human perception that causes the problem! Hackberry’s growth rate is very fast in its youth and slows as it matures, but it should grow 20-25 feet in 10 years.