Abstract Size of individual trees in an 18-year-old yellow-poplar, plantation varied with location in the stand. The 2.1-acre study area is at the down-slope end of an old field that had been abandoned from agriculture at least 10 years prior to being planted with yellow-poplar. Effective soil depth had been reduced in some parts by severe erosion and had been increased in other parts by deposition. Dominant and codominant trees ranged from 10 to 58 ft high and from 1 to 11 inches in diameter. Repeated early dieback in the poor site area was attributed to drought. The tallest trees started height growth before others and were still increasing their growth superiority 18 years after being planted. Soil and foliar analyses indicated that environmental factors influencing or determining available soil moisture were most closely correlated with tree heights.