Hi, Kami, You’re dealing with runners or suckers. Most lilac plants spread this way (one variety, Miss Canada lilac (Syringa x prestoniae, does not send out as many as most others; other “safe,” suckerless options include Meyer lilac, Peking, and Manchurian lilac).
What to do? There are not a lot of options. As you’ve learned, covering the runners will not stop them. One solution may be to install barriers, or edging, that you bury about 6 inches or more below ground level. Use a steel or metal edged type. First cut (at ground level or as low/deep as you can) and pull the existing runners, then put in the barrier. It should reduce or stop the runners for a few seasons.
Hi, Kami, You’re dealing with runners or suckers. Most lilac plants spread this way (one variety, Miss Canada lilac (Syringa x prestoniae, does not send out as many as most others; other “safe,” suckerless options include Meyer lilac, Peking, and Manchurian lilac).
What to do? There are not a lot of options. As you’ve learned, covering the runners will not stop them. One solution may be to install barriers, or edging, that you bury about 6 inches or more below ground level. Use a steel or metal edged type. First cut (at ground level or as low/deep as you can) and pull the existing runners, then put in the barrier. It should reduce or stop the runners for a few seasons.