Lilac invasion!

[RoseValleyRambles]

Hi folks,
I have what I think is a big lilac as part of my hedge. Below it is a relatively narrow raised bed, about 1 foot. Last year, I totally cleared it of invading lilac (with a hefty dose of elbow grease). But it keeps on making fresh attempts to take over! Any good strategies for keeping it at bay?

[shovetheholly]

Some lilacs send out suckers quite freely - it's one of the more annoying habits they have! Others are fairly sucker-free. If the tree is on your side, and the problem is very severe (and it sounds pretty bad) I would honestly be tempted to remove and replace it with a non-suckering variety.

Alternatively, I think you would need to maintain it very regularly, by cutting back suckers as soon as they appear. Avoiding cutting the tree back very hard can also help as a heavy prune encourages this root growth.