I've never grown mint, but my suspicion is that edging won't make any difference. I've heard that the roots can escape the bottom of a pot, so edging would be easy.

Joe Pye Weed's root system is huge and tough as nails. It could probably grow through concrete - LOL! Every other year I just dig out the outer parts with a spade to keep it where I want it. Bee-balm creeping roots are pretty shallow, so perhaps it could be contained. I just pull out where I don't want it each spring.

Who ever said perennials are low-maintenance - ha!

My mom planted mint in a big, deep plastic pot with the bottom cut out. I'm not sure if it grew out from under the pot, but the stems flopped over and rooted outside the pot, plus seedlings appeared some feet away from the mother plant. So, I'd have to say No, lawn edging would not be an effective containment system for mint.

For anything as tall as Joe Pye Weed, I'd guess you'd need something about a foot deep - and my JPW spreads more by seedlings than by spreading.

I do use both steel and plastic edging - 4" wide - to keep the grass out of the beds. I still have to monitor that edge, but it's fairly effective. I use it along with bricks for a mowing strip. It's much better than bricks alone, since they're not quite deep enough to stop the grass (plus, there are gaps between the bricks, of course).

Hey Deanna

We've had great success corraling mint by burying them
in large black plastic pots/containers and/or 5 gallon buckets with holes drilled in the bottom(depending on the size of the plant)

The lawn edging definately slows down grass encroachment, and looks nice and neat, but not a permanent barrier.

Watch out for Joe Pye! I's a cool plant, the winter birds appreciate the berries-but he is a thug when established. The tap root was massive!

Good luck with the mint-it's nice to have around(on your own terms)