Snip stems from the outside of the plant, using shears, if you only need a few leaves for fresh use. Choose stems that are at least 4 inches long with fully mature leaves.
Cut back the entire mint plant if you need large quantities of mint or are preserving it. Trim all the stems to within 1 inch of the ground. The plant grows back from the remaining stems.
Harvest the entire mint plant a second time after it regrows and the stems reach a length of 6 to 8 inches long. Alternatively, harvest the entire plant right before the flowers open, when the leaves contain the most oils, if you plan to dry the leaves for later use.