Growth, dry-matter partitioning, and specific mass of lamina of black maple (Acer nigrum Michx.f.) and sugar maple (A. saccharum Marsh.) irrigated at 10-, 26-, and 42-day intervals were compared. Total dry mass, stem length, and surface area of lamina were greater for sugar maple than for black maple for plants irrigated every 10 days. Reducing irrigation frequency curtailed growth of both species, but the reduction was greater for sugar maple than for black maple. The shoot: root ratio was lower for black maple than for sugar maple and was reduced by drought in both species, particularly among plants irrigated every 26 days. Specific mass of lamina increased as plants aged, was greater for black maple than for sugar maple, and decreased in response to irrigation at 42-day intervals. The slower growth, lower shoot: root ratio, and greater specific mass of lamina of black maple indicate this species has a greater capacity to withstand drought than sugar maple.