A lilac will generally start to sucker when mature. The suckering process allows the plant to renew itself by growing new shoots from the base and the sides of the plant.
Tools You Will Need For Propagation:-A sharp and clean shovel-A pot or container to place the clump of roots-Soil to pot up the new plants-A hori hori knife
Dig a circle around the shoot with a shovel, approximately six inches to a foot away from the stem. Sever the sucker from the main root with the sharp shovel blade.
Once you have the clump dug, you will be able to use a smaller tool, such as a hori hori knife, to separate and cut the smaller suckers away from the clump.
Each stem will be able to be divided from the clump and grown on as an individual plant. Make sure that each lilac shoot has roots attached for planting.
Provide your new lilac plant with some extra care at this time, by caring for it in the container until it recovers from the stress of separation, from the parent plant.