In early spring, I had purchased two mint plants from the produce department of a grocery store—those plants sold as fresh herbs you’re supposed to throw out once you’ve removed the leaves to season your dinner. I left them on my screened porch, watered them as-needed, potted them up once, and eventually transplanted them into my herb garden. Cooped up in their tiny nursery pots, both plants had produced rhizomes with new plants emerging every half inch or so. I told some of the story here.
Mint is dangerous. Yes, I’ve said it before. I’ve said it so many times I’m sure I’ve given the impression I despise mint, but that impression is wrong. I love mint. My favorite ice cream flavors are Peppermint Stick and Mint Chocolate Chip (particularly Turkey Hill All Natural Mint Chocolate Chip). I’m also partial to mint in Middle Eastern and Indian cooking.
I like mint so much that I bought a chocolate mint plant a few days ago to add to my herb garden; eventually I may have half a dozen varieties. Despite the mint love, I charge mint as among the most dangerous plants to have in or near your kitchen garden.
After a single growing season, two mint plants jammed a root-retaining ring with rhizomes—at least three rhizomes lie on the surface, hugging the inside wall and traveling once around or more. The root barrier ring is 24 inches across meaning each rhizome is a bit longer than six feet. I’m confident that the longest make two trips around the ring; I’ve seen mint rhizomes that have grown 16 feet in a single season.
I wrote about this garden terror first in an article titled Protect your Small Kitchen Garden from Mint and more recently in the article, More Mint Madness. The recent article included photos of a mint plant moments after I removed it from its nursery pot—I’ve included one of those photos at the beginning of this post.
My Mint Today
After one growing season, and a severe winter, I inspected the mint installation in my herb garden. I had planted mint within a thick plastic root barrier that reaches about 12 inches into the soil. The barrier is a circle about 30 inches across and by the end of the growing season, mint filled it and spilled over onto surrounding soil. (I peeled back the escaping stems and stuffed them inside the root barrier circle.)
Six days after I captured the preceding photo, baby mint plants emerged from the rhizomes in the retaining ring. Keep in mind this started as two small plants in nursery pots last spring… if I don’t hack out some rhizomes and roots this season, the stupid mint plant(s) will choke themselves to death. No they won’t. I’m convinced they’ll figure out how to eat plastic if they think they need to to survive. I’m keeping my eyes on the mint; no way am I letting it escape the root barrier. By the way, if you ever trim your mint plants to keep them under control, compost them only if you have a self-contained system such as a compost tumbler. Once a rhizome reaches a passive compost heap, you’ll have mint babies poking up wherever you apply compost.
When snow finally melted off my garden, the mint leaves were gone. Mint stems were everywhere inside the root barrier. Without the barrier, it’s clear there would be mint rhizomes extending at least 9 feet into my herb garden and under my lawn. In fact, by now there would be dozens of mint plants pushing up in a nine foot circle around the original mint plant.
Photos emphasize my point: Mint is aggressive and prolific. It WILL take over once you get it started… so don’t. Don’t start it in the soil in your garden. If you’re going to grow mint, contain it—either absolutely in a container that gives the plant no opportunity to touch soil in your yard, or within an inviolable barrier that stops the roots and lets you keep the stems off your garden soil.