Moisture availability during the warm season is also a property of Alfisols, which are present in the western portions of the range of white basswood, but it is not a property of Entisols and Mollisols. Although rare at very low elevations, basswood is occasionally found on the Coastal Plain but appears with increasing frequency in the upper Piedmont. However, it is not a major species in any of them. White basswood flowers in the latter part of June and early July. Once flowering begins, flowers, pollen, and nectar are abundant.
Nocturnal pollinators produce somewhat less fruit set than diurnal pollinators.
Although insect pollination is predominant, wind pollination plays a minor role. The fruits are borne in clusters of six or seven on bracts. The bracts, which are shaped like long, slender leaves, may serve as wings for the purpose of wind dispersal or may function primarily as flags to attract nocturnal pollinators. Seed Production and Dissemination White basswood seeds ripen in September and October following pollination and are dispersed in the winter and spring. Little information exists on fruit set and seed dispersal of this species.