Lilac -- Pruning

Lilac should be pruned after blooming each spring. Remove one-fourth (1/4) of the plant starting the fifth year after planting to encourage new basal shoots. Remove old wood at ground level. Never cut the entire plant back by one-fourth (1/4) across the top.

Pruning encourages better flowering and reduces insect problems such as lilac borers which attack thicker, older wood.

Pruning also allows for better air circulation, limiting the amount of powdery mildew.

For more information on pruning, see Pruning and Care of Trees and Shrub, University of Illinois Publication #U5040.