I have a lilac tree. It's about 9-feet high. I have it planted 6 feet from my neighbor's wall. They are worried the roots will damage their foundation. Can you tell me if this will do that?
Lilac Tree Roots
Certified GKH Gardening Expert
It is highly unlikely that the lilac will cause damage to a foundation. They have very non-aggressive root systems and this is why you often see them used as foundation plants. The only way that it could be a threat (and even then, the plant would probably die before it did damage) would be if the roots were restricted tightly, as in there were only a few feet for the roots to grow in. That does not sound like the case where you are, so the lilac is not a threat.