I never thought lilac was a poorly behaved shrub, but I'm finding that mine is getting a bit crazy. When we bought the house in 2007, there was a healthy lilac bush next to the front steps. It used to be surrounded by grass that got mowed. However that was in a difficult steep area and I ultimately decided to landscape that whole side of the house with native plants and mulch.

What I have noticed is that anywhere there is no plant cover to compete, the lilac sends up new branches and stems like crazy. I mean huge, bushy new growth every year. I feel like my lilac is trying to take over that whole area!

Is this common or is mine acting weirdly? There is only one thing I can think of that might have happened.... there used to be a honeysuckle growing right in with the lilac. I pulled it out the best I could and killed the remaining with roundup, but I remember when doing that it almost seemed like the honeysuckle was grafted onto the lilac. I was able to kill it, but I'm just wondering if some of the honeysuckle's aggressiveness was bred into my lilac and it's a crazy cross of some kind?

I know that makes no sense.... but it's all I got! So tell me, is this normal behavior for a lilac? Anything I can do other than hack it back each year to keep it in check?