It's relatively common knowledge that if we give it the chance, mint will take over the world.
I don't particularly want the mint to take over my world. So I contain it. This is the part of the herb garden that contains the mints. (This is early March.)
You can't see it real clearly, but the mints are planted in what appear to be planter pots submerged beneath the surface of the soil.
These are 30" sections of PVC water pipe. They were left over from a development in the area a few years ago, and I was given them for this purpose. I cut them into reasonable lengths and buried them in the soil. Thirty inches is deeper than even mint roots are able to go, so we're safe from the mint apocalypse, at least for now.
To help them drain, I filled the bottom foot or so with 1" drain rock, with a foot of good soil, and another foot of good compost over that. The area between the pipes is mulched to help keep other weeds and things down.
I'm not pleased with the spacing, so I put other things (including chives) in between, often just setting a planter (tarragon? savory? oregano?) on top of the mulch between them.
The red door greenhouse is new, but this herb garden has been in place for a few years (even if the mint is kind of weird this year!). It works well.