Mint isn't just useful in the kitchen. This unexpected herb is a mosquito-fighting secret weapon. You can use it to make a natural pesticide spray for your plants. Even planting it in the garden will help repel pests — both exoskeletal and fur-covered. In other words, growing mint is a DIYer's dream. But you can't make any of these things if your mint doesn't last the winter. To make sure it does, you need to give it a somewhat aggressive haircut and a cozy layer of mulch before the first frost. If you live in a frigid climate, consider bringing your plant (or plants) inside to ensure they survive until spring.
There are numerous types of Mentha (mint) species, each with its own unique characteristics. In the United States, people typically only grow a small selection of these varieties in their gardens. This includes popular culinary spearmint, beloved apple mint, and the toxic pennyroyal, which is often used as a groundcover plant. Most mint plants reach a maximum height of 1 meter, although they are often much shorter. Mints are hardy herbaceous perennials and can survive harsh winters in USDA Hardiness Zones 3 to 8 by going dormant and directing energy to their roots. With proper care, they will sprout again in the spring.
Leave it out
Just before the first frost is expected in your area, harvest all the edible leaves from your plant, then take your scissors, garden shears, or, for large shrubs, electric hedge trimmers and chop the stems of your mint plant to the ground. Be aggressive! Your mint will thank you for it come spring. Next, cover your plant with mulch, twigs, leaves, or even an old bedsheet will do. If you're expecting a lot of snow or deep freezes, wrap pots in garden fleece or bubble wrap or top them with planks of wood.
Alternatively, relocate the planters to a sheltered, windless spot — beside walls, in a cold frame, or the doorway of your garden shed. Karen Gibson, Master Garden and founder of the blog Sprouted Garden, goes a step further, wrapping her potted mint plants with old sheets, popping them in a plastic storage container, and overwintering them in her unheated garage. Another reason to overwinter your mint indoors is if it's planted in an attractive ceramic pot. Clay often cracks through successive freezes and thaws. Keep your plant in a warm, bright spot inside (like a sunny kitchen windowsill), and you might even be able to harvest fresh mint throughout the cold season!
Make more
When trimming your plant, you may notice runners, also called stolons. These hefty roots help the mint colonize new areas, even taking over your garden without careful observation. Planters of mint quickly get overcrowded with stolons. Pull up the excess, chop them into 1 to 2-inch pieces, and plant them in sprouting trays. Place these trays in a sheltered spot in your garden, a greenhouse, or even a sunny windowsill inside. Give each tray about a cup of water once a month for the duration of winter — the same goes for your cut-back mature plants. As the weather warms, they'll sprout, and you'll have mint seedlings for your spring garden.
It is important to regularly check your mint plants during the winter to ensure they are not waterlogged. If the soil feels soggy or shows signs of mold or moss, or if there has been heavy rainfall or melted snow, it is recommended to place risers under the planters. This will prevent the roots from rotting. While mint is generally resistant to diseases, one to be cautious of during the winter is mint rust, scientifically known as Puccinia menthae. The spores of this fungus can survive in the soil and roots of mint plants during the cold season, slowly infecting them. In the spring, you will notice clear signs of infection, such as orange, brown, or black spots on the leaves and distorted stems. It is advised to regularly inspect all your plants, whether they are cuttings or fully grown, for any signs of rust. If any plants are infected, it is important to discard them along with the soil they are growing in.
