Common lilac bushes grow about 1 foot per year when mature. Young lilacs grow much more rapidly, leveling off as they grow older. A fully matured specimen can reach 20 feet tall and 12 feet wide.
Lilacs prefer soil with a pH of 6.5 to 7.0 and need good drainage. Any necessary pruning should be done right after the bush finishes blooming, as flower buds for the following year are set just before the lilac becomes dormant in the fall. Lilac blooms can be a variety of colors, ranging from lavender and pink to white and yellow. Properly cared for lilac bushes can live for centuries.