Pruning Lilac Bushes

If you are fortunate enough to have a Syringa (lilac) or two or three or more, you will eventually need to know about pruning lilac bushes. Lilacs are in the olive family (Oleaceae) and originate from Europe and Asia. Ranging from about 6 ½ to 33 feet (2 to 10 meters) tall, depending on the variety, lilacs bloom with flowers a little less than half an inch (1 centimeter) in diameter. The flowers are usually purple, though some lilacs produce light pink or white flowers.

Depending on the source, pruning lilac bushes can be a yay or nay thing. Some experts insist it should be done regularly in order for the shrub to grow and bloom properly. Others claim that leaving a lilac bush completely alone is best because, if left alone, the plant grows and blossoms as Mother Nature intended and, after all, who knows better than she?

If You Choose to Prune

But if you happen to belong to those who subscribe to the belief that while Mother Nature tries, she does not always know everything, especially about pruning lilac bushes. It is true that without pruning, the bushes of this plant can become extremely dense and woody. If this is not your desire, by all means, you should definitely prune your lilac bush, but do so with care.

Pruning lilac bushes takes some knowledge about this plants blooming habits. Unlike hydrangeas, for example, which bloom only on new growth, lilacs bloom only on old growth. Therefore, never shear lilacs to the ground as you may occasionally do to a hydrangea. Prune new growth on lilacs only right after blooming has finished to avoid inadvertently cutting off branches that would otherwise produce blossoms the following spring.

Careless Pruning Penalties

Pruning lilac bushes incorrectly can result in the plant not blooming for anywhere from one to five years! So, if blooms are important to you in the overall scheme of your landscape design and if pruning lilacs is one your agenda, the important thing to do is make sure you trim them right after they have bloomed, but before they buds for next years show.

Pruning lilac bushes also should come into play if insects or diseased branches are evident. Cleaning out old, dead limbs helps aerate the center of the bush and helps keep it healthy. Pruning also allows you to shape the bush as desired, but be forewarned: You may be cutting off potentially blooming branches when you prune for shape only!

Prune to Move

Another reason for pruning lilac bushes exists when you want to move them from one place to another. Not only will need to prune the branches judiciously, you need to root prune them, as well. This takes some forethought and should be done the early spring before you plan to move them in the fall.

Using a sharpshooter shovel, dig around the base of the plant into the earth as though you were planning on moving it, but do not lift it up out of the ground. This severs enough roots so that the remaining ones form a denser, more fibrous root-ball system when you actually do move the plant come autumn.

Whether or not pruning lilac bushes is on your to-do list, enjoying the plant is the most important thing. If it makes you feel better to baby your lilac, then by all means, go for it! A little TLC never hurt anything. Just do it with care and thoughtfulness, and your lilac will reward you with a generous, show-stopping blossom performance for many years to come.

See Also:

Pruning Techniques for Roses