Hello, I have a small lilac plant in my garden. It keeps spreading its roots and popping up in unwanted places. I really don’t want the plant.mom happy to give it to someone. How do I make sure when I dig it up that it doesn’t just keep popping up? It’s spindly, about 5 years 9th and 6 feet tall. Thank you.
Thank you for contacting the Toronto Master Gardeners. As you note, a challenge with Lilacs (Syringa) is that they spread readily by root shoots, also called suckers. If you want to be able to grow this plant elsewhere on your property or give it to someone else, it may be easiest to transplant some of the emerging shoots. However, if you want to move the entire shrub, the best time to do so would be in early spring (you may lose blossoms if done in the spring) or fall. The Toronto Master Gardeners Guide Planting a Tree for Life outlines the best way to plant (or re-plant) a tree or shrub Planting a tree for life .
If you are just removing the shrub and not worried about transplanting it, cut back the branches to a foot or two from the ground. This will make it easier to manage and give you something to hang on to during the removal process. With a spade or shovel dig around the shrub in a circle as wide as the drip line (to the edge of the crown). Lilacs send out shoots to this distance and sometimes beyond. You will need to dig deeply enough to get under the root ball. Remove as much of the root and soil as you can as this is key to preventing future regrowth and suckers. Check any soil that you replace in the hole for obvious root shoot pieces. Lilacs can regrow from small shoot fragments.
You may still have a few suckers poke up from bits of remaining shoots but this will decrease over time. It is best to dig around and pull shoots up by hand rather than cutting them off. This way you remove as much of the sprouting shoot as possible.
Best of luck with the removal and / or transplanting your Lilac shrub!