Japanese Tree Lilac, Syringa reticulata

Ivory Silk tree lilac in bloom. Photo from Jardin Jasmin, France

Lilac season is always too short; did you know there’s a way to prolong it? Yup, and not only that, but this cousin of our more common lilac bush is a sturdy tree that performs well here in the Pacific Northwest no matter which side of the mountains you’re on.

The most commonly found cultivar of the Japanese tree lilac (Syringa reticulata), is ‘Ivory Silk’. This tree reaches a height of approximately 20 feet and width of 15 feet with an upright, spreading shape that becomes more rounded with age.

The tree lilac’s most prominent features are the blossoms. In early to mid-June after most other flowering trees are done with their spring display, Ivory Silk bursts with a profusion of large creamy-white flower panicles (a loose branching cluster of flowers), some of which may be up to 12 inches long.

The fragrance of the Japanese tree lilac does not match that of the shrub form, but other tree characteristics more than make up for that shortfall.

Ivory Silk blossoms. Photo from New England Nurseries.

The leaves are similar to the common lilac shrub: dark green and oppositely attached to a shiny brown, stout stem. Bark on the strongly-built trunk is also a shiny cinnamon-brown, with prominent lenticels (small, raised pores) that lend winter interest. Ivory Silk tree lilac is quite hardy, able to withstand winter temperatures as low as 30 degrees below zero Fahrenheit. Not sold yet? The tree lilac also has few pest or disease problems.

A closely related tree gaining popularity is the Chinese tree lilac, Syringa pekinensis (also known as S. reticulata ssp. pekinensis). The Chinese tree lilac grows a bit bigger in both height and canopy width: 30 feet tall and 20 feet wide. Although easy to train as a single-stemmed tree, it may also be found as a large multi-stemmed shrub.

Other attributes are quite similar, including hardiness and pest and disease resistance. Cultivars of the Chinese tree lilac include China Snow, Great Wall, Copper Curls, and Beijing Gold.

Both of these trees are great additions to a small urban yard and are tough enough to use as street trees too. The next time you need a hardy, compact, utility-friendly, flowering tree, look beyond those dogwoods and crabapples. Try a flowering tree lilac instead; you won’t be disappointed in this tough, elegant little tree!