Lilacs are fragrant flowering shrubs that are easy to grow and remarkably vigorous and long-lived. They are suitable for planting in both large and small gardens. In addition, you can stagger blooming times by planting a variety of cultivars.
Lilacs or Syringa belong to the Oleaceae family. This botanical family includes various plants that are very important in agriculture, silviculture and horticulture, including ash and olive trees, forsythia and jasmine.
There are some twenty natural and hybrid Syringa species. Most of the natural species are native to southeastern Europe and eastern Asia, especially China. Lilac shrubs vary in height depending on the species, and bloom in a wide range of colours.
The main lilacs
Syringa vulgaris, the common lilac so beloved by our grandmothers, is native to southeastern Europe. It was introduced to Central Europe in about 1563 by Ogier Ghislain de Busbecq, Austrian Ambassador to Constantinople (Istanbul). The forms with single violet or white blooms that are such a familiar part of our rural landscape were brought to North America by early European immigrants.
In the late 19th and early 20th century, various lilac cultivars were created in Europe, by the famous French breeders and nursery growers Victor and Émile Lemoine, among others. These new cultivars were dubbed French lilacs, designating the group of common lilac cultivars that bloom in late May*. The number of Syringa vulgaris cultivars has continued to grow, thanks to the work of European and North American breeders. The Royal Botanical Gardens, in Hamilton, Ontario, is today the international registration authority for new lilac cultivars.
Another group of lilacs, known as hyacinth lilacs (Syringa x hyacinthiflora), includes hybrids between S. vulgaris and S. oblata. These lovely shrubs flower early (around mid-May) and, depending on the cultivar, have highly fragrant single or double flowers. The Clarke’s Giant cultivar has one of the largest flower panicles in this group.
A third group, named Syringa x prestoniae, or Preston lilacs, in honour of Isabella Preston, of the Ottawa Experimental Farm, includes hybrids bred from a cross between S. reflexa and S. villosa. These vase-shaped lilacs bloom later (around mid-June) than the first two groups. Their leaves are ruffled and their small tubular flowers are lightly scented. These lilacs produce few if any suckers.
A fourth group includes some lovely Asian lilacs: Amur tree lilacs (S. reticulata ssp. amurensis), Japanese tree lilacs (S. reticulata ssp. reticulata) and Peking tree lilacs (S. reticulata ssp. pekinensis). Some cultivars in this group can grow up to eight metres tall. These species may be grown as trees or shrubs. They are late bloomers (early July), with creamy white flowers and gold-hued bark. S. reticulata 'Ivory Silk', a very popular cultivar, has a more tree-like shape than the species.
The hybrid species Syringa x chinensis has attractive small, dense leaves and small pale mauve flowers that appear in early June.
Syringa x persica is a highly prolific bloomer, with strongly fragrant pinkish-lavender flowers.
Syringa villosa is a vigorous bushy shrub that makes a good container plant. It flowers profusely in mid-June.
Syringa meyeri ‘Palibin’ is a compact, dwarf cultivar (1.5 m), suitable for a hedge or rock garden. It can also be found top-grafted. The small pale mauve flowers appear in mid-June. Some years, the small, delicate leaves turn a lovely orangey colour in fall.
Syringa patula ‘Miss Kim’ is another small, compact lilac. It produces pale mauve flowers in mid-June and is suitable for planting as a specimen or for use as a screen. The leaves may turn burgundy in fall.
Syringa ‘Bailbelle’, sold as Tinkerbelle, is a dwarf cultivar with tubular pale pink flowers. It is a hybrid of S. microphylla ‘Superba’ and S. meyeri ’Palibin’.
Lilacs can be used in a wide variety of ways. They may be planted as specimens, to form hedges or screens, in rock gardens or as patio plants. The following growing tips will help you keep your lilac vigorous and encourage abundant blooms.