Turn that pot right side up and put the plant IN it, then plant the whole thing to keep those underground spreaders from roaming.

For things like mint that can also flop over and root, leave a rim of about 2 inches.

Yes, that would certainly work as well. I don't have enough big pots to do that. I grow mints between our barn and gravel driveway which naturally limits their spread but still gives a very casual look.

I like the sound of that!

I love this idea

Good idea. Bone.

Suspect that the death part is key (for runners that break out)!