Typically on mesic alluvial and lowland sites, Quercus nigra also occurs on a wide variety of soil types and in a diversity of habitats.

Trees with 3-lobed leaves with attenuate bases have been recognized as Quercus nigra var. tridentifera Sargent.

Quercus nigra reportedly hybridizes with Q . falcata (= Q . × garlandensis E. J. Palmer), Q . incana , Q . laevis (= Q . × walteriana Ashe), Q . marilandica (= Q . × sterilis Trelease), Q . phellos (= Q . × capesii W. Wolf), Q . shumardii (= Q . × neopalmeri Sudworth), and Q . velutina ( Q . × demarei Ashe). In addition, D. M. Hunt (1989) cited evidence of hybridization also with Q . arkansana , Q . georgiana , Q . hemisphaerica , Q . laurifolia , Q . myrtifolia , Q . palustris , Q . rubra , and Q . texana.