Technical Abstract: Controlled environment studies with potato frequently assume responses from single-stem potato plants can be extrapolated to the field where multiple-stem plants are common. Two controlled environment studies were conducted in order to characterize differences in canopy growth, development, and dry matter production among single- and multiple-stemmed potatoes. Leaf area distribution was significantly influenced by stem density, with mainstem and apical lateral branch leaf area 150 to 200 percent larger in triple-stemmed (3S) versus single-stemmed (1S) potato pots (p < 0.01), while basal lateral branch leaf area was 50 percent less (p < 0.01). Basal lateral branches were more developed in 1S pots with longer branch lengths, more leaf area, and higher orders of branching. In the second experiment, more leaves were initiated in higher density pots; however, individual leaf areas were approximately 50 percent smaller when compared to those in 1S pots. Total leaf area and total, vegetative, and yield dry matter production were unaffected by stem density in either experiment on a per pot basis. The development and growth of lower basal lateral branches in the single-stemmed potato canopy offset any initial advantage in leaf numbers in the multiple-stemmed plant. These results appeared to validate the assumption that, given a late maturing cultivar and adequate nutrition, responses from single stemmed plants can be extended to multiple stemmed plants when expressed on a production area basis. These findings have practical considerations for potato researchers who conduct growth chamber experiments and potato modelers.