The aroma and flavor of fresh mint makes the trouble this herb can pose in the garden well worth it. Mint has a tendency to spread and take over a garden bed, quickly choking out other nearby plants. This becomes a nuisance as cutting it back only works for a short time before the roots and leaves spread again. A little planning before you plant your mint keeps the plant under control and prevents it from spreading to other areas of the garden.
Choose a 12-inch diameter pot that is at least 12 inches deep. Cut the bottom off the pot with a sharp utility knife.
Dig a 10-inch deep hole in a well-draining, sunny garden bed. Make the hole as wide as your plastic pot. Place the removed soil on a nearby tarp.
Add 1 part compost and ½ tbsp. fertilizer to the soil on the tarp. Mix this together thoroughly.
Set the bottom-less pot inside the hole so that the top 2 inches of the pot protrudes above soil level. Fill in the center of the pot with the soil you removed from the hole until the soil level inside the pot is at the same level as the rest of the garden bed.
Plant the mint seedling in the buried pot at the same depth it is at in its nursery pot. Firm the soil around the plant with your hands, then water thoroughly so any air pockets in the soil collapse. Add more soil if necessary, to maintain the soil level inside the pot. The pot will prevent the roots from spreading underground.