Almost everyone has heard of peppermint. That’s the flavouring they use in toothpaste and chewing gum, isn’t it? Yes, it is, but a peppermint plant in your home garden can offer you so much more. Learning how to grow peppermint is easy, but before we get into growing peppermint, let’s learn a little bit about the plant itself.
Peppermint (Mentha x Piperita) was first cultivated in 1750 near London, England as an experimental hybrid between watermint and spearmint. That you can now find naturally growing peppermint almost anywhere in the world is a testament not only to its adaptability but as an indication of its medicinal qualities.
Once our forefathers, or more likely foremothers, learned how to use the peppermint plant, they took it everywhere they moved or visited where some, no doubt, was left behind with new friends.
Growing Peppermint Plant from Seeds
Peppermint adds long-lasting colour and fragrance to ornamental herb gardens with its dainty, lavender-coloured flowers and intensely fragrant leaves. It is a hybrid species and rarely sets viable seeds, but the few viable seeds produced can be used to grow additional plants. Because the tiny seeds dislodge easily from the soil, the best practice is to germinate them indoors roughly eight to 10 weeks before your location’s average last frost date. Once established, the resulting peppermint plants can be grown in pots or planted directly in an outdoor garden.
1) Combine equal portions of finely milled sphagnum moss and perlite in a bucket. Add water until the mixture feels saturated to your touch. Stir the mixture periodically, distributing the moisture. Let the water soak into the mixture until the sphagnum moss becomes plump.
2) Pack the sphagnum moss-perlite mixture into 3-inch-diameter starter pots, leaving the top 1/2 inch of each pot empty. Firm the moist mixture into the bottom of each pot to collapse all air pockets. Use your fingertips to rough, or rake, gently the top 1/4 inch of each pot’s sphagnum moss-perlite mixture, which is the growing mixture.
3) Sprinkle five or six peppermint seeds onto the surface of the growing mixture of each pot. Space the seeds at least 1/4 inch apart. Press the seeds gently onto the growing mixture to anchor them. Do not cover the seeds with the mixture because light aids seed germination.
4) Set the starter pots near a sunny, south- or west-facing window with no heavy curtains or exposure to outdoor shade. Position a fluorescent lamp 10 inches above the pots to provide supplemental light if needed. Keep the light on for roughly 14 hours each day during the seed germination process.
5) Set the pots on a heating mat to provide the right germination temperature. Warm the pots to above 70 degrees Fahrenheit during the day, and turn off the heating mat at night to mimic the normal warming and cooling cycle of soil.
6) Cover the pots with a propagation dome or a sheet of clear, plastic wrap. Either device keeps the peppermint seeds from drying out. Lift the dome or plastic wrap every day, and check the moisture level of the pots’ growing mixture. Mist the peppermint seeds with water whenever the mixture’s surface feels barely damp.
7) Watch for the first peppermint seedlings to appear two to four weeks after you sowed the seeds. Remove the propagation dome or plastic wrap and the heating mat after the rest of the seeds germinate and seedlings appear. Remove the weakest peppermint seedlings by snipping them off at their base with small scissors, and allow the most robust seedlings to grow.
8) Keep the fluorescent lamp in place if you supplemented the natural light with such a lamp. The lamp’s light will prevent the seedlings from becoming leggy,
9) Rotate the pots by 180-degree increments weekly. The rotations prevent the peppermint seedlings from leaning toward their light source. Provide water when the soil dries out beneath the surface. Apply water directly to the soil rather than misting entire plants. Doing so decreases the chances of fungal and bacterial growth on the plants’ leaves.
10) Transplant the peppermint plants when they produce several sets of mature leaves. Put them in individual planters filled with potting soil, or transplant them directly into an outdoor garden’s soil after all danger of frost has passed, spacing the plants 12 inches apart.
- Use plant pots with multiple bottom drainage holes, which allow excess soil moisture to drain.
- Position indoor peppermint plants close to a south- or southwestern-facing window that receives at least four hours of sunlight daily.
- Peppermint may become invasive if planted outdoors. Keep it in a pot or install a root barrier if you grow the plant outdoors.
Peppermint Planting and Care of Peppermint
Although the care of peppermint is a little more involved than just sticking it in the ground, it certainly isn’t intricate. First and foremost, this plant needs lots of water and it is often found naturalized by streams and ponds where the soil is rich and the drainage is good. It won’t tolerate dry conditions. While partial sun is sufficient for peppermint, planting it in full sun will increase the potency of its oils and medicinal qualities.
Though not as invasive as some of its mint relatives, no instructions on how to grow peppermint would be complete without mentioning its tendency to spread. Because of this, many gardeners prefer growing peppermint in containers. Others grow it in the ground with wood or plastic edging buried around the bed to prevent the spread of roots. Whatever method is chosen, good care of peppermint includes moving the plants to a new location every three or four years. They tend to weaken and become spindly if left in the same place for too long.
There are two main cultivated varieties of this aromatic herb: black and white. Black peppermint has deep purple-green leaves and stems and a higher oil content. The white is actually light green and has a milder flavor. Either is adequate for growing peppermint at home.