Ecotypic, clonal, and racial variation present in tree species across their native ranges represent a largely untapped opportunity to select superior seed sources or clonal materials to withstand a variety of unique environmental stresses imposed in built environments and managed landscapes. This paper focuses on three important woody plant genera (Quercus L., Platanus L., and Taxodium Rich.) and researchers’ efforts to discover superior genotypes with tolerances to environmental stresses, including alkaline soil conditions, moisture deficits, and temperature extremes. The study authors are also interested in exploiting geographic provenances and open-pollinated family selection to identify unique genotypes or populations having desirable ornamental attributes, rapid root regeneration potential, and/or desirable plant architecture. A discussion of current results, potential impacts on selection of urban forest trees for managed landscapes, and plans for future development and research are presented.