What is a Lilac?

A lilac is a shrub or tree in the genus Syringa, native to Eastern Europe and the temperate regions of Western Asia. Lilacs are immensely popular in gardens all over the world, and some cultures have specific associations with these aromatic, brief-blooming flowers. Many garden supply stores in temperate zones carry lilacs, often with several cultivars on offer, and it is also possible to order lilacs directly through nurseries which specialize in these trees and shrubs. With over 200 named lilac cultivars to choose from, gardeners have a great deal to work with.

Lilacs are deciduous, producing deep green, simple leaves in the spring which eventually change color and drop off in the fall. Their flowers may be white to purple, with a particularly distinctive purple shade being known as “lilac.” Lilacs usually produce cone-shaped clusters of flowers which may appear in the late spring or midsummer, depending on the region and the cultivar, and the flowers often fade quickly.

The aroma of lilacs is very strong and quite memorable. These plants like sunny spots in the garden with lots of room to spread and slightly alkaline soil. The color of the flowers can vary slightly, depending on the chemical composition of the soil and the region, which is something to be aware of when purchasing lilac cultivars from a nursery. Water requirements for lilacs vary, depending on the climate, with the plants preferring moist, but not wet, soil.

Caring for lilacs is quite simple, because they do not like to be pruned. Lilacs produce flowers on old wood, and if a lilac is pruned, it will put out a lot of new green growth, but no flowers. As a result, gardeners prune lilacs sparingly, and usually immediately after the plant has flowered, to give it a chance to recover before the following year. As a result of lack of pruning, lilacs tend to develop a rakishly shaggy appearance which some gardeners find very pleasant. This sprawling growth habit also makes lots of room for lilacs very important.

Some gardeners refer to the butterfly bush in the genus Buddleja as a lilac or “summer lilac.” Although butterfly bushes look very similar to lilacs, they are not quite as aromatic, and they benefit from pruning, preferring to be substantially cut back at the end of the growing season so that they can put out new growth in the following year. Butterfly bushes also have very different foliage which makes them easy to identify.