08/04/2020

Japanese/Chinese Tree Lilac

The Ohio Chapter ISA continued efforts is to advance responsible tree care practices through research, technology, and education while promoting the benefits of trees. This Tree-Of-The-Month is commonly known as the Japanese Tree Lilac (Syringa reticulata).

The Syringa reticulata, commonly called Chinese tree lilac or the Japanese Tree Lilac, typically grows as a small tree or large shrub. Japanese tree lilac was introduced into cultivation in 1876. In tree form, it grows to 30’ tall and 20’ wide with an oval-rounded crown. Its best ornamental feature is its showy, fragrant, creamy white flowers which bloom in upright panicles to 12” long in late spring to early summer (later than most other lilac species). Some gardeners dislike the privet-like smell (sweet) of the flowers. Flowers give way to lose clusters of brown capsules that persist into winter. Reddish-brown peeling bark is attractive on younger branches, gradually turning gray with age—Sharply-tipped, lanceolate to ovate, dark green leaves (to 6” long). The tree in the fall can have yellowish colored leaves in some cases to no fall color.

Genus(Syringa) name comes from the Greek word syrinx, meaning tube or pipe in reference to the pith-filled but easily hollowed stems of some genus plants. The specific epithet (reticulata )means netted-veined about the leaf veins.

Syringa reticulata subsp. reticulata is native to Japan and is sometimes commonly called Japanese tree lilac. Syringa reticulata subsp. pekinensis is native to China and is sometimes commonly called Chinese tree lilac or Peking lilac. Syringa reticulata subsp. amurensis is native to Korea and eastern Russia and is commonly called Amur tree lilac or Amur lilac. Both are found growing natively on cliffs and in the scrub, usually on limestone.

It is easily grown in average, medium moisture, well-drained soil in full sun. Tolerates light shade, but best bloom occurs in full sun. This tree prefers organically rich, moist, slightly acidic soils with good drainage. Tree lilac should be sited where it gets good air circulation. This tree remarkably tolerates urban conditions. To the extent practicable, faded flower panicles should be removed prior to seed set. Prune as needed immediately after flowering. Best growth typically occurs in cool summer climates.

The Japanese /Chinese Tree Lilac is winter hardy to USDA Zone 3-7.

Planting Requirements

Japanese tree lilac is tolerant of urban conditions, growing in poor, clay, or alkaline soil. Regular irrigation during dry spells helps make this a pest-resistant tree.

Check with a local Ohio International Society of Arboriculture Certified Arborist for what cultivars will work in your location.

Cultivars

‘Ivory Silk’ was selected in 1973 by Sheridan Nursery in Ontario, Canada. It is a little smaller than the species with a height of up to 20 feet. Trees bloom at a young age and are compact with a dense, rounded form. It is a prolific bloomer that makes an excellent street tree or specimen.

Ethnobotany

It is well known that lilac blossoms are edible, though they smell much better than they taste. A springtime delight is to make a lilac cold-water infusion. Simply fill a glass pitcher (or a large glass) with fresh lilac blossoms then add water. Allow steeping for an hour. You can choose to strain before serving in glasses or remaining in the water and simply refilling. So long as you are getting scent from them as you drink, you can keep reusing them.

Scatter a few lilac blossoms on fresh green salads. The blossoms can be candied and preserved to decorate desserts later in the year. Lilac-scented honey is the ultimate treat when it comes to combining the health goodness of local, unpasteurized honey and the intoxicating scent of lilacs. All you must do is choose a sterilized jar and fill it with lilac flowers. Let infuse for about six weeks – and there is no need to strain afterward! Enjoy on bread or drizzled over a bowl of fresh-cut fruit. Remember, though; only the flowers are the edible part of lilac.

 

Research has shown that lilacs are great for our eyes. In a Scientific American article, it was reported that among the significant determinants of floral color are carotenoids (organic pigments found predominantly in plants), especially lutein. Lutein and zeaxanthin are the only carotenoids found in the retina and lens of the human eye.

In flowers of the lilac, the lutein is contained in a highly specific, rare form not found in many other foods. This has been linked to improved eye health, specifically, reduced risk of macular degeneration and cataracts.

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Tree Selection Tips
The Ohio Chapter ISA recommends working with an ISA Certified Arborist when selecting or caring for any tree in your landscape. To better guide you on the vital plant information for the Japanese/Chinese Tree Lilac use our friendly users guide below:

Genus	Syringa
Plant Family	Oleaceae
Life cycle	Perennial woody
Origin	Eastern United States
Habitat	Full Sun
Tree form	Oval-Round
Does it produce shade?	Yes
Soil	Prefers organically rich, moist, slightly acidic soils with good drainage.  Needs good air circulation.  Tolerates urban conditions well.
Bloom season	June very showy.
Fruit/Seed	Brown capsules
Plant height	20-30 feet
Plant spread	15-20 feet
Growth rate	Medium
Suitable for planting under or near electric (utility)	Yes/No-Depends on height of wires
Potential Concerns	No serious insect or disease problems.  It reportedly has good resistance to some of the major pests of lilacs, such as powdery mildew, scale and borers.  It has some susceptibility to additional diseases including blights, leaf spots, wilt and ring spot virus.  Additional insect pests of note include caterpillars and leaf miner.  Flower buds are susceptible to frost injury in early spring.

Written by Mark A. Webber BCMA, CPH, LTE,  MArborA, OCMNT, TRAQ

 

Literature Sources:

 

https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=c152 (Collected on July26,2020)

https://bernheim.org/learn/trees-plants/bernheim-select-urban-trees/japanese-tree-lilac/ (Collected on July 26,2020)

https://edis.ifas.ufl.edu/st611 (Collected on July 26,2020)

https://www.ediblewildfood.com/blog/2016/06/lilac-flowers-for-eye-health/ (Collected on July 26,2020)

https://www.nutraingredients-usa.com/Article/2010/07/15/Marigold-dominates-eye-health-ingredients-supply (Collected on July 26,2020)

 

Photograph sources Mark A. Webber 2020