Fruiting branchlets of Cornus florida were artificially defoliated to determine the extent and nature of reproductive adjustment in this species. Infructescence abortion and fruit abortion increased in response to defoliation, but only fruit abortion was statistically significant. Defoliation significantly decreased fruit size. Reproductive adjustments were roughly proportional to the extent of defoliation, with fruit set decreasing about 6% and fruit biomass decreasing about 8 mg per leaf removed. Fruit development continued even after complete defoliation, indicating significant assimilate production of developing fruits and/or ability of branchlets to draw assimilate from neighboring branchlets. We conclude that in flowering dogwood assimilate supply controls the number of filled fruits and the rate at which they grow.