White-bark birches, such as paper birch (Betula papyrifera) and European white birch (B. pendula), are popular landscape plants in the North, but not widely grown in the South. Southern gardeners desirous of growing these white-bark birches often don't know which selections grow best in their warm, humid climate. A recent study can help. Researchers at the University of Arkansas, Fayetteville, have tested various birches to determine the best for landscapes in the Southeast.
Researchers grew 20 birch species and selections in two Arkansas locations (one in USDA zone 6 and one in USDA zone 8) for four years to evaluate their growth, ornamental qualities, and performance.
The best performing white-bark birch selection was 'Royal Frost'. This European birch reveals its white bark while still young. The bark color contrasts well with the burgundy-purple foliage that turns bright orange in fall. 'Royal Frost' not only performed better than other white-bark birches in the study, it even outgrew the native river birch (B. nigra). Another highly rated white-bark birch was the Asian white birch 'Dakota Pinnacle' (B. platyphylla 'Fargo'). It features a narrow, upright, pyramidal growth habit.
As expected, the native river birch grew well, but the cultivar 'Dura-Heat' grew even better, especially during the heat of summer.
The complete report of Betula for the South was in the April 15, 2007, issue of American Nurseryman Magazine. It can be ordered online at: American Nurseryman.