Most swamp hardwood stands contain many defective and diseased trees. Many unmanaged, fully stocked hardwood stands contain no desirable advanced black ash regeneration. The tree has coarse ascending branches and a slender, sometimes bent or leaning trunk which extends almost to the top of a narrow crown. The bark is shallowly fissured and divided into large irregular plates with thin, soft, papery scales that rub off easily. The fruit is an elongated, winged, single-seeded samara that is borne in terminal or axillary clusters.
Black ash regenerates through sexual and vegetative reproduction.
The seed contains a dormant embryo that requires stratification and a period of cold temperatures for good germination. Sprouts originate from adventitious buds on the sides of the stump and at the root crown. Stump sprouts can exhibit fast growth. Black ash is most commonly found growing in moist to wet muck or shallow organic soils. It also grows on fine sands and loams underlain by clays and on other poorly drained sites with high water tables.