Find a partially shady area for your mountain mint. While getting established, young plants enjoy a rich, moist soil and shade environment; mature plants can tolerate drought.
Prepare the soil for planting. Turn the dirt over with a spade and remove debris from the planting site. Break apart soil clods with your hands, then rake the soil flat with a landscape rake.
Dig a furrow 1 inch deep. Sow mountain mint seeds in the furrow, leaving 3 to 4 inches between seeds. Cover over with soil to complete the planting.
Water the soil to moisten it, then maintain a moist soil until seeds germinate within a couple weeks.
Weed out competing plants so your mountain mint can develop. Continue to weed the garden bed all season long.
Water the growing mint to saturate the soil, then allow it to dry out thoroughly before watering again.
Cut mountain mint down in the autumn as part of your fall cleanup.