Did you know Hackerry, Celtis occidentalis, trees are tolerant of air pollution? Now that's sustainability folks! Sites subject to air pollution would not seem ideal areas for growing trees. Given adequate soil preparation and aftercare, however, Hackberry trees perform just as well as they would in places enjoying clean air. These trees like shaded areas and love rain gardens! They are massive in scale and typically grow to be 40-60' (less frequently to 100') in height. They tolerate drought, clay soil, and wet soil. They're low maintenance and even attract birds and butterflies.