Powdery mildew is a prevalent issue with common lilac but does little permanent damage to the shrub.

Hundreds of cultivated varieties are available of various heights with flower colors ranging from white to cream to rose, lavender to purple. Shrubs can also be single or double flowered and reblooming varieties are also available. Several varieties are also grafted on standards as “tree lilacs.”

Lilacs should be pruned shortly after blooming, as pruning later in the year reduces or halts next years bloom. Lilacs can be pruned to maintain a pleasing shape and or to control size. They also benefit from rejuvenation pruning on older bushes to remove dead or old wood.