Mint is a rapid growing perennial herb that grows up to 3 feet tall and is quite aggressive. It’s rhizomes, or root system, sends out runners to form and establish more plants that makes it a difficult plant to control and remove permanently.

Usually, one of the best ways to remove unwanted plants is hand pulling. Since you have a field of mint this might be a daunting task. With a larger area a hoe, or at least a hand tool, may work better. Whatever method you use, you need to remove all of the plant. If you leave any of the underground parts, rhizomes or runners, they will regenerate. That being said, it is not possible to remove every piece of the root system the first time through. Your field will need to be constantly surveilled to look for reappearing plants and to continue to pull or hoe them. The number of plants that reemerge will greatly decline, but it will take several years to completely get rid of the mint. If you do not persist in watching for new mint plants it could easily get out of hand again. Be sure everything you pull or dig up is disposed of in a bag and placed in the garbage.

Depending on the size of the area, cover the mint with black plastic or cardboard. Be sure not to leave any gaps that might allow light to shine through to “feed” the mint. The longer you can leave it on the better, some say 6 weeks, but others say a whole season.

If possible, using both methods, first pull/hoe, then cover, will give the best results.

The following article gives additional details: Roll Up Your Sleeves: Use Multiple Strategies to Control Invasive Weeds.

If you would like to contact mint farmers about how they control their mint crops and if there is a market for yours, the internet would be your best resource.