Pekin lilac (Syringa pekinensis Rupr.), a tree lilac native to northern China, has many desirable horticultural traits but is underused as a landscape plant (Dirr, 1998). A combination of pest resistance and superior ornamental characteristics makes it desirable for reduced maintenance landscapes. Pekin lilac differs from the closely related Japanese tree lilac [S. reticulata (Bl.) Hara] primarily by its finer texture and variable colorful bark, which exfoliates horizontally in thin flakes or sheets. In North Dakota trials, both species usually flower at the same time, but the blooming date may vary slightly among seedlings, cultivars, and sites. Pekin lilac flowers in May in central North Carolina and in June in eastern North Dakota. The later flowering date for tree lilac species extends the season of bloom for lilacs. Within populations of S. pekinensis grown from seed, there is considerable genetic diversity in leaf size and winter hardiness of individuals. Several cultivar selections have been introduced to the nursery trade, including Beijing Gold ( Zhang Zhimjing ), China Snow ( Morton ), Pendula , and Summer Charm ( DTR 124 ) (Dirr, 1998). Although shrubby lilacs are often selected on the basis of color, quality, and fragrance of the flowers, SunDak is a new tree lilac cultivar selected primarily for its attractive exfoliating orange to coppery pigmented bark on the trunk and lateral branches, which provides landscape interest throughout the year. This environmentally durable cultivar fulfills consumer preferences for a low-maintenance small landscape tree with pest resistance (Tripp and Raulston, 1995).