Mint plants, found in the genus Mentha, are a group of mostly perennial herbs with a fresh and aromatic scent that are used in cooking, making teas and essential oils, and as an insect repellent. There are many different species within the genus, and mint plants hybridize easily, making for a vast amount of diversity in appearance, scent, and flavor. All types have underground roots, lightly serrated leaves (emerging in pairs on opposite sides of the square, central stalk), and white to purple flowers which will draw pollinators. Watch out, though! Mint is an underground bully and loves to invade the rest of your garden with its quick-growing roots. Keep it contained in a pot underground if you’d like to avoid a hostile takeover.
Spearmint is likely the best known type of mint around the world thanks to its sweet smell and more mild flavor compared to its cousin, Peppermint. Also, unlike Peppermint, whose leaves grow off of branches with purple flowers, Spearmint leaves grow almost directly from the central stalk with pinkish flowers. This variety of mint is believed to have originated in the regions of Europe and Asia, but since its beginnings, it has dispersed rapidly and has become naturalized in numerous countries everywhere.
Seed:Not recommended as mint seeds can be very slow to germinate.
Vegetative: Can be propagated by taking stem cuttings or by dividing mature plants. Root cuttings in a sterile media or a jar of water.
Cutting Depth: 2″
Space Between Plants: 12–20″
Space Between Rows: 18–24″
Rooting Soil Temperature: 70–77°F
Days for Rooting: 10–35
Start Indoors: Cuttings are best taken in spring or fall.
Start Outdoors: Anytime after soil temperatures are 65°F or higher.
Grows best in moderate climates. It’ll grow as a perennial down to USDA Zone 5 but will go dormant and die back during the winter. In very cold winter climates, it needs to be brought inside or into a greenhouse. You can also try using winter protection like a heavy layer of mulch over the roots or a floating row cover.
Natural: Full sun or partial shade.
Artificial: Grows well under fluorescent and metal halide HID lamps. Provide at least 8 hours of light daily.
Soil: Prefers well-drained loamy soil rich in organic matter; however, mint is adaptable and will do well in most soil types. A pH of 6.0–7.0 will keep your mint plants happy and healthy.
Soilless: Container-grown plants will do well in a soilless mix containing peat moss, perlite, and vermiculite.
Hydroponics: Thrives in a variety of hydroponic systems, including deep water culture.
Aeroponics: Thrive in aeroponic systems. Rooting cuttings using aeroponics will provide new plants quickly and efficiently.
Water: Requires moderate levels of water—more when first getting established. Container grown plants will need to be watered more frequently to prevent drying out. Consistent moisutre will result in the best growth.
Nutrients: Requires moderate levels of nutrients. Prepare soil before planting using compost and aged manure to provide organic matter. Side dress with compost once annually in the fall before plants go dormant. Overfeeding can cause disease problems.
Pruning: Regular harvests or pruning of the top third of each stem will promote bushier, fuller growth. Pinch off flowering stalks to redirect the plants’ energy into leaf production. In fall, you can cut the whole plant back to just above the ground to prepare for winter dormancy.
Mulching: Use mulch to conserve soil moisture and suppress weeds. A heavy layer of mulch over dormant roots will also help plants to survive deep frosts.
Other: It’s important to note that mint plants will spread rapidly using their underground runners. To prevent garden takeover, plant in containers or inside of a metal ring sunk 10 inches underground.
Pest(s): Rarely bothered by pests, but watch for:
Deficiency(s): A nitrogen deficiency will result in reduced yield. Potassium and phosphorus are also important nutrients used by mint, and deficiencies will cause yellowing or browning of the outer edges of leaves.
Companions: Grows well with asparagus, celery, carrots, cucumbers, parsley, onion, pepper, and tomato. However, it’s best to grow mint in a container within or close to your garden plants to prevent its roots from spreading. Believe us, it’s worth it, because mint provides pest protection for your other crops and attracts pollinators.
Harvest: Mint leaves are best cut in the morning when still cool but after any dew has dried. Harvest time can begin as soon as 60 days after transplanting, but be sure to not take more than 1/3 of the young plant’s leaves or you might stunt its growth. Once well-established, you can cut plants back to the ground once per season for a big harvest.
Storage: Fresh leaves will keep for 5–7 days in the refrigerator if loosely wrapped in a plastic bag, though they’re best used fresh. You can also store cut stems in the refrigerator placed in a jar of water with a plastic bag covering the tops. Dried leaves should be stored in a dark, cool, dry place in an airtight container.
Fun Fact: The US is responsible for the vast majority of global spearmint production, with most cultivation being done in the Pacific Northwest, most notably Washington State and Oregon.
Preserve: Fresh mint leaves can be dried for later use. Tie bundles together and air dry upside down, using paper bags to cover the mint and prevent the color from fading while ensuring adequate air flow to prevent molding. Remove dried leaves from the stems. Mint leaves can also be chopped and frozen in ice cube trays with water or preserved as mint jelly.
Prepare: Fresh leaves are used to make tea, flavored desserts and drinks, and as an ingredient in cake or bread recipes. It’s also seen in chutneys, sauces, salad dressings, and soups. Try making home-made spearmint ice cream, a delight in the heat of summer.
Nutritional: Provides vitamin A and dietary fiber. Also contains small amounts of vitamin C and some B vitamins.
Medicinal: Mint is used to prevent stomach aches and nausea and treat indigestion. It is also a diuretic and anti-inflammatory and can be used for treating toothaches, sore muscles, and congestion. Topically, a dilute mixture of the essential oil can be used to help treat skin irritations and relive headache, fever, and menstrual cramps. Compounds found in mint are being studied for their anti-cancer properties.
Warnings: The concentrated essential oil is an irritant if used on skin or inhaled. Mint should not be used in excess by pregnant or nursing women.
Who says mint juleps are just for the Kentucky Derby? Try this classic Julep Drink the next time you’re feeling fancy. And don’t forget the big hat!