It’s rare to have a woody tree that can offer so much lengthy, seasonal interest in the landscape. The China Snow tree lilac (Syringa reticulata subsp. pekinensis ‘Morton’) is such a tree with significant ornamental contributions of gorgeous late spring flowers and very ornamental, copper-colored, exfoliating bark. Toughness, consistent habit and applicability in a wide range of landscape situations, including residential use, parks, parkways, wide medians and under utility lines, will continue to make this selection more popular and available in the coming years. Some sources use the older, but still very common, nomenclature of Syringa pekinensis and common names include Chinese lilac, Peking lilac and Pekin lilac.
With Japanese tree lilac (Syringa reticulata) selections having their own run with popularity, China Snow, a Chicagoland Grows Introduction, really has become the “poster child” for the value and impact of ornamental bark in our gardens, parks and streetscapes. This selection is thought to have a finer texture than Syringa reticulata and certainly more impactful ornamental bark and winter interest. China Snow has also won an Award of Garden Merit from the Royal Horticultural Society.
This variety was selected from seed-started collections at the Morton Arboretum (Lisle, Illinois). The original seed has an interesting and notable history with original collection for the Arnold Arboretum by Joseph Rock in Gansu Province, China, in 1926. Some of that seed arrived at the Morton Arboretum later that year and the parent tree of China Snow is now 45 feet tall and 40 feet wide. The heart-shaped, opposite leaves offer a dark green, semigloss contribution in the summer months and the variable fall color is typically a respectable yellow. The creamy white, fragrant flowers (on 3- to 6-inch panicles) in June are remarkable and consistently appear every year and will last for two to three weeks with decent coloration. Fading flowers will become grass-green, loose capsules that later transition to tan and add persistent interest over the winter months. The cinnamon-colored, exfoliating bark is truly amazing with younger stems showing more of a smooth glossiness and older trunk and stem portions really contributing significant peels and flakes. Intensity of exfoliation seems to increase with age but also has some variability between specimens of a similar size and age. Regardless, the contribution of ornamental bark is significant and beautiful and looks great 365 days of the year.
This member of the Oleacea (olive) family is certainly hardy in Zones 5-7, although some more recent sources are listing hardiness from Zones 4b-7b. With a moderate growth rate, this selection will become a medium sized tree with an average height of 25 feet and width of 20 feet after 20 years. Offered as either single-stemmed or multi-stemmed specimens, the form is upright and spreading with a more rounded form with advancing age. Most pruning should be accomplished after flowering as is typical with the genus. Full sun situations are ideal, although partial sun will be tolerated but will create a looser, more open form with less flowering. With the heavy contribution of ornamental bark throughout the season (particularly in winter of course), low branched specimens are fairly common. Dr. Jim Ault of the Chicago Botanic Garden makes the comment in terms of tree placement for the appreciation of the bark…“which is especially notable where the tree can be backlit in the winter sun.”
China Snow tree lilac has no serious insect or disease problems and has some resistance to bacterial blight, powdery mildew, scale insects and lilac borers. There is susceptibility, however, to some leaf spots, wilt and ring spot virus. Open areas with better air circulation help with possible foliage problems although there is an inherent and notable mildew resistance compared to some other Syringa species. Deer don’t seem very interested in nibbling on this plant although butterflies, hummingbirds, bees and other pollinators enjoy the showy bloom period as well. Moderately tolerant of clay soils, dry soils and drought, this selection is not picky about pH and will accept both acidic and alkaline conditions. However, good drainage is absolutely vital. Overly wet or poorly drained soils will be problematic for this selection and affect health and longevity. The ideal planting space for this tree would include organically rich, slightly acidic soils with excellent drainage.
There are some additional varieties of S. reticulata subsp. pekinensis to consider with different traits than China Snow. All of these selections maintain the wonderful ornamental bark. One of the most popular is Beijing Gold (‘Zhang Zhiming’) which features conspicuously golden yellow flowers and a mature height around 20 feet tall. Great Wall (‘WFH2’) has more upward sweeping branches which creates a narrow form with only a 12- to 15-foot width at a height of 20-25 feet. Lastly, Summer Charm (‘DTR 124’) was introduced by Willett Wandell and is known for a slightly finer foliage texture, uniformity of habit and perhaps a slightly increased hardiness.
Mark Dwyer was the Director of Horticulture at Rotary Botanical Gardens in Janesville, Wisconsin, for 21 years. He has degrees in landscape architecture and urban forestry and now operates a private consulting practice, Landscape Prescriptions by MD. www.landscapeprescriptionsmd.com