It's the time of year when noses and eyes are directed to the beauty and fragrance of certain plants. A genus of plants well known for both is Syringa, known commonly as lilac. Lilacs offer gardeners a large variety of plant shapes, sizes, and flower colors. The parade of lilac flowers begins in late April and early May and continues through mid-June. Hybridizers have worked extensively with the common lilac resulting in over 1000 different varieties. Some lilac species to look for include:
Syringa meyeri, Meyer Lilac, grows 4 to 8 feet tall, and 6 to 12 feet wide forming a dense, broad-mounded shrub. Flowers are violet purple in color and occur on panicles 4 inches long and 2 1/2 inches wide. They emerge before plants are fully leafed out, usually early to mid-May. This species is not affected by powdery mildew as are many other species.
Syringa microphylla is commonly known as the littleleaf lilac. The foliage is about 1/4 the size of the common lilac, medium green in color above, grayish green and pubescent beneath. The plant grows 6 feet tall and 9 to 12 feet wide. Flowers are rosy lilac in color. The panicles are just 1 1/2 to 2 1/2 inches long and appear in late May to early June. The variety 'Superba' has single deep pink flowers.
Syringa patula, the Manchurian lilac, has an upright form and grows 9 feet tall. The flower panicles often occur in pairs from the terminal buds of last years growth. They are 4 to 6 inches long with lilac purple flowers and appear in late May to June. The commonly available variety, 'Miss Kim', grows 5 to 6 feet tall (sometimes taller) and 4 to 5 feet wide.
Syringa reticulata, the Japanese tree lilac, grows 20 to 30 feet tall with a spread of 15 to 25 feet forming an oval to rounded-shaped small tree. The large, fragrant white flower panicles appear in early to mid-June. 'Ivory Silk' is an excellent cultivar that flowers well when young and has a more compact growth habit. Additional varieties include 'Chantilly Lace', 'Regent', and 'Summer Snow'. A related species, Syringa pekinensis, the Pekin lilac, is a smaller tree, growing just 15 to 20 feet tall. It is often multi-stemmed and finer in texture than the Japanese tree lilac. The flowers are creamy white on 3 to 6 inch long panicles in late May to June.
Syringa villosa, the late lilac, grows 6 to 10 feet tall and 4 to 10 feet wide providing a dense plant for the shrub border. The rosy lilac to white flowers appear in mid to late May sometimes continuing into June. The flower panicles are 3 to 7 inches long. Crosses between S. villosa and S. reflexa have resulted in the well known Preston lilacs. Nodding lilac, Syringa reflexa, grows 10 to 12 feet tall and wide. The purplish pink flowers are produced on 4 to 10 inch long panicles. This species is not fragrant and is hardy for growing zones 5 to 7.
The common lilac, Syringa vulgaris, grows 10 to 15 feet in height with a spread of 6 to 12 feet. The flowers are extremely fragrant and appear in early to mid-May on panicles originating in pairs from the terminal buds. Numerous varieties are available with white, violet, blue, lilac, pink, and magenta flowers. Varieties are available with single and double flowers. The Chinese lilac, S. x chinensis, is a hybrid between S. x persica and S. vulgaris. This shrub is round-topped with arching branches. It flowers more profusely than the common lilac and grows 8 to 15 feet tall with a similar spread. Flowers are purple lilac in color and appear in mid-May. Syringa x hyacinthiflora are crosses between S. oblata and S. vulgaris. These hybrids are extremely hardy and flower before the common lilac hybrids.
The cutleaf lilac, Syringa laciniata, has a low, dense, mounded form. Plants grow 6 to 8 feet tall and wide. The flowers are pale lilac in color and appear all along the stems. They occur in May. The foliage is lacy and fine-textured.
Syringa x persica, the Persian lilac, is a graceful shrub with upright, arching branches. Plants grow 4 to 8 feet tall and spread 5 to 10 feet. The foliage is bluish green. Flowers are pale lilac in color and fragrant. They appear in mid-May. A nice plant, but often severely affected by powdery mildew.
Although lilacs offer just one season of performance, they are still an asset in the landscape. The large shrub types are best used for borders or groupings rather than close to the house. The tree forms are excellent in locations requiring low-growing trees.
This article originally appeared in the May 26, 1995 issue, p. 77.
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on May 26, 1995. The information contained within may not be the most current and accurate depending on when it is accessed.