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Plant Focus
Making Southwest U.S. Oak Cultivars Available
Mark Krautmann
Published May 2019 in International Oaks No. 30: 225–232
Abstract
The woody flora of the U.S. Southwest is rich with oaks, a northward extension of Mexican Quercus spp. that includes more than 240 species and thousands of interspecific hybrids.
The ornamental U.S. nursery trade reliably offers many kinds of grafted oaks for the eastern half of the nation. In the West, however, oaks are not similarly popular as landscape plants, and nearly all nursery-grown Western oaks are propagated from seed.
Because our nursery propagates woody deciduous landscape species, we aim to make exceptional young ornamental oaks from the American Southwest consistently available for garden center customers. We propagate a wide variety of new selections of Southwest oaks in order to diversify our customer base and to lead the ornamental market for some of the best oaks from the American Southwest.
Among the most serious threats to oaks of the West is our rapidly warming climate and associated pest threats. Will oaks from 1,000–1,500 km further south in latitude be needed for the constructed landscape in order to tolerate a hotter, drier U.S. Western climate? Most agree. Oaks adapted to the Southwest offer not only great ornamental appeal, but economic benefits such as reduced fire danger for homeowners and office parks (less leaf litter), and lower maintenance costs for irrigation, pruning, disease or insect control. Few nurseries propagate more than a handful of seedlings or grafts of oaks of the American Southwest, an anomaly when one considers the tens of millions of residents of major urban areas of the West.
Keywords
U.S. nursery trade, oak cultivars, Quercus macrocarpa, Quercus gambelii, Quercus ×undulata
References
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