Lilacs offer gardeners a large variety of plant shapes, sizes, and flower colors. Hybridizers have worked extensively with the common lilac resulting in over 1000 different varieties. There are seven color classifications for lilacs: white, pink, violet, blue, magenta (reddish-purple), lilac, and purple. Flowers are also available in single and double forms.
Below are several species of lilac that grow in Iowa. They are roughly listed by bloom time from earliest to latest.
Early Flowering Lilac | Common Lilac | Meyer Lilac | Manchurian Lilac | Chinese Lilac | Cutleaf Lilac | Persian Lilac | Littleleaf Lilac | Preston Lilac | Late Lilac | Nodding Lilac | Japanese Tree Lilac | More Information
For early blooms, try Syringa × hyacinthflora, commonly called the early flowering lilac. These hybrids between S. oblata and S. vulgaris are well-suited for cold climates and bloom in mid to late April. Plants grow 8 to 10 feet tall and wide and can develop a reddish purple leaf color in the fall.
Cultivars of Early-Flowering Lilac
*VF = Very Fragrant
The Common Lilacs or French Hybrid Lilacs, Syringa vulgaris, are most noted for their bloom size and fragrance. There are thousands of cultivars available, some dating back to the late 1800's. These became known as French Hybrids due to the work of Victor Lemoine, a French hybridizer, who bred about 200 different lilacs in the 1870's.The common lilac 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.
Cultivars of Common Lilac
|Adelaide Dunbar||Purple||D||10-12||VF||Fairly resistant to mildew|
|Avalanche||White||S||9||F||Father Fiala hybrid|
|Agincourt Beauty||Violet||S||10-12||F||Late midseason bloomer|
|Albert Holden||Violet||S||7||F||Silvery undertones|
|Charles Joly||Magenta||D||10||VF||Fairly resistant to mildew|
|Charm||Pink||S||8-10||VF||Large blue-pink florets|
|Edmond Boissier||Purple||S||12-15||F||One of the darkest|
|Krasavitsa Moskvy||White||D||12||MF||Four sets of petals|
|Leon Gambetta||Pink||D||12||F||Profuse bloomer|
|Ludwig Spaeth||Purple||S||12-15||F||Large, narrow panicles|
|Miss Ellen Willmott||White||D||12-15||VF|
|President Lincoln||Blue||S||15-20||VF||Truest of the blues|
|Sensation||Bi-color||S||10||F||Purple with white edges|
*MF = Mildly Fragrant; F = Fragrant; VF = Very Fragrant
Syringa meyeri, Meyer Lilac, grows 4 to 8 feet tall, and 6 to 12 feet wide forming a dense, broad-mounded shrub. These lilacs produce smaller flower clusters than most lilacs (4 inches long and 2 1/2 inches wide), but make up for their lack of size with shear number of blooms. The lilac to violet blossoms have a spicy fragrance. These are great foundation plants because of their compact size (6 feet at maturity) and freedom from disease. 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 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.
The Chinese lilac, Syringa × chinensis, is a hybrid between S. × 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.
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 × 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.
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.
For later blossoms, try one of the Preston Lilacs, Syringa × prestoniae, a cross between S. villosa and S. komarowii subsp. reflexa have resulted in the well known Preston lilacs. Preston lilacs have elongated leaves that are more resistant to powdery mildew. Their flowers have a spicier fragrance that is milder than many of the French hybrids. Plants are reliably cold hardy to USDA Hardiness Zone 3.
Cultivars of Preston Lilac
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.
Nodding lilac, Syringa komarowii subsp. 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.
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. The fragrance of the flowers is privet-like. It is one of the hardiest trees on the list, as trees are hardy to zone 3. Trees are also noted for their smooth, dark cinnamon colored bark.
'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.