Lilac Collection

Fun Facts

Perhaps the best known lilac species is common lilac (Syringa vulgaris), represented by the hundreds of cultivars within this species. Common lilacs bear large, fragrant flower panicles composed of many small individual florets that have either a single or double form. Cultivars are classified by flower color.
In the late 1800s the Lemoine nursery in France introduced many new cultivars to the world—the term “French Hybrids” is often still used in nurseries in reference to all common lilac cultivars.
The lilac species Syringa oblata subsp. dilatata is notable in two seasons. It is one of the earliest blooming lilacs in the spring (before common lilacs), bearing large clusters of pretty pale pinkish lavender florets. It shines again in autumn when its foliage develops bronze to purplish tints—one of few lilacs that show fall color. The cultivar ‘Cheyenne’ has especially nice fall foliage.
Most lilacs have simple, unlobed leaves with a rounded, oval, or obovate shape, but within the lilac collection you may notice a couple of exceptions. Afghan lilac (Syringa protolaciniata) and its cultivar ‘Kabul’ have simple leaves that are laciniate (deeply lobed), though the degree of laciniation can vary from leaf to leaf. Even more unique is Syringa pinnatifolia, the only lilac species with compound leaves.
Dwarf Korean lilac (Syringa meyeri ‘Palibin’) is one of the smallest lilacs in the collection, growing only about 3 to 4 feet tall and wide. It is densely twiggy, fine textured, and has a neatly rounded habit. In mid to late spring dwarf Korean lilac is covered with a profusion of short flower panicles; the small florets are light lavender pink.
Most lilacs grow as multi-stemmed shrubs, but several species grow as small trees with one or a few main trunks. Japanese tree lilac (Syringa reticulata) is a popular tree-form lilac, and a venerable 1876 specimen (accession 1111*A) of this species is the oldest lilac at the Arboretum. Japanese tree lilac blooms several weeks later than common lilacs and bears large terminal panicles of very small, creamy white flowers.

About

There are 407 lilac plants representing 173 taxa (kinds) in the Arboretum’s collection. These include 135 cultivars that have been selected for certain horticultural merits such as flower size and color. The remaining kinds represent various botanical taxa, the parents of many of today’s hybrids. Together they provide a season of color and scent that extends over five weeks each spring. The Arnold Arboretum has celebrated lilacs and the arrival of spring with an annual celebration, Lilac Sunday, since 1908.

Resources:

Find directions and accessibility information for this collection
Read about lilac history, care, cultivars, and fragrance
Read about the history of Lilac Sunday [pdf]
Visit the International Lilac Society website

Illustration of Syringa chinensis by Charles Faxon

164-96*A

‘Lilac Sunday’ Rouen Lilac

Scientific Name: Syringa × chinensis ‘Lilac Sunday’

The Arnold Arboretum introduced a lilac called ‘Lilac Sunday’ in 1997. This garden favorite can produce clusters of flowers that are more than two feet long.

Lilac Sunday with flowers viewed from distance to see full form

36-2002*A

‘Purple Haze’ Lilac

Scientific Name: Syringa ‘Purple Haze’

An alumna of Arnold Arboretum propagator Jack Alexander’s lilac breeding program, this sterile hybrid was introduced in 2005. Its abundant, pale purple flowers kiss the sky early in the lilac blooming season.

Syringa 'Purple Haze' by Kyle Port in lilac collection

Explorers Garden Tour

This quarter-mile tour through the Explorers Garden features stories from the Arboretum’s century and a half of collecting plants around the world. If you’re at the Arboretum, click here to take a version of this tour with Expeditions, our mobile web app.

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