The common lilac (Syringa vulgaris) is a plant introduced throughout the United States from the southern portions of Europe. The species is a widely used ornamental, known for its fragrant purple flowers that are familiar to nearly everyone. Multitudes of lilac cultivars exist, with many different features. The common lilac bush can provide years of vivid flowers with the proper care.
The University of Connecticut Plant Database describes the common lilac bush as an upright shrub that loses its leaves each year. The common lilac can achieve heights of up to 15 feet and normally grows to at least 8 feet high. The bush can be as wide as 12 feet and it lacks any leaves on its lower branches. The heart-shaped leaves grow in pairs opposite each other on the twigs and are a dark shade of green.
The lilac flowers typically bloom during the month of May and possess a distinct pleasant aroma that fills the air around the bush. The individual flowers are small and appear on 4-inch to 8-inch long panicles, a term that describes a cluster of flowers that develop at the end of a branch. While the common lilac bush will produce purple flowers, the many hybrids of the plant can produce flowers ranging from white to blue.
Plant a lilac bush in the full sun for the best results in terms of both growth and flowering potential. The species is easy to transplant and needs to go into well-draining ground with a slight acidity to the soil. The common lilac bush often will suffer from a disease called powdery mildew, which affects the leaves and brings a whitish film onto their surfaces. The disease is not serious unless it attacks the bush year after year.
The University of Illinois Extension Homeowner's Column website states that lilacs may flower poorly if they are in a shady part of your property. If you make the mistake of pruning the lilac bush late in the season, you risk killing off the next year's buds that will develop into flowers. The best time to prune lilacs is right after the bush finishes flowering. Prune down the older branches right to ground level, as these older branches will not produce as many vigorous flowers as the younger ones will.
Few shrubs offer the choices in cultivars that the common lilac does. President Grevy is a 12-foot tall hybrid with blue flowers, while the President Lincoln cultivar's blooms are even bluer. Charles Joly has purple buds and magenta flowers. Katherine Havemeyer is a renowned pink hybrid and Monge provides you with purple flowers on long stems. The Miss Ellen Willmott and Edith Cavell hybrids produce showy white blooms. Dappled Dawn has variegated leaves of green and yellow with purple to blue flowers.