Mint is one herb I won’t live without. I enjoy the occasional mojito, but my favorite way to enjoy mint is as an herbal tea. I use dried mint leaves to brew both hot and iced tea, and in the summer I make a weekly batch of sun tea with the fresh leaves. Since mint is notorious for its rampant growth (it can quickly take over the garden), I grow my mint in patio containers. I also grow mint year-round indoors. This means I have fresh mint leaves to harvest 12 months of the year. Today, I’d like to share information on how to grow mint indoors using three different techniques.
Why grow mint indoors
Mint (Mentha species) is a perennial that produces new foliage all year long if the stems are not killed by frost, making it one of the easiest herbs to grow inside. There are hundreds of different species, hybrids, and cultivars of mint. Some are more common than others when it comes to their flavor and popularity. Unlike many other herbs, mint is very easy to grow indoors, as long as you give the plant enough light and consistent moisture (more on both of these in a later section). Mint also makes a surprisingly beautiful houseplant. I love mint’s crinkly green leaves and how the stems of some varieties tumble down over the sides of the pot. I’ve even had mint plants bloom indoors in the dead of winter.
Yes, mint is attractive, but most of us don’t grow herbs for their good looks. We grow them for their flavors, and what could be better than snipping your own fresh, homegrown mint leaves to make a cup of hot tea on a cold day? Since mint is constantly making new stems and leaves, you’ll always have a few sprigs ready for harvest.
Another reason to learn how to grow mint indoors is for the fragrance. Whenever I need a little pick-me-up on a dreary day, I simply pinch off a leaf, rub it between my thumb and index finger, and inhale. The fragrance of mint is energy-boosting and invigorating. You can even toss a few leaves into your bath water for a fragrant, muscle-soothing soak.
One final benefit of growing mint indoors is a lack of pests. Aside from the occasional fungus gnat, I’ve never had any houseplant pests attack my mint plants.
Sourcing mint plants for indoor growing
When considering how to grow mint indoors, your thoughts might first turn to sourcing the plants. You have several options. For me, the easiest route is to purchase a starter plant at my favorite local nursery. However, if it’s autumn or winter and you’re just learning how to grow mint indoors, you might find your local nursery out of stock. Most nurseries carry herb plants only in the spring. If this is the case for you, consider starting a new mint houseplant from a root division or a stem cutting.
- Sourcing an indoor mint plant from a root division:
If you already have a mint plant growing in a container or in the ground – or if you have a friend or family member who does – it’s easy to dig up a division of the plant, pot it up, and bring it indoors. As long as there is a section of root attached to a stem, it’s a viable division. You can start with a large division or a small one. Mint grows fast, so even if you start with a tiny division, before you know it, the plant will fill your pot.
- Sourcing an indoor mint plant from a stem cutting:
This method of growing mint indoors only requires a severed mint stem about 3 inches long. Mint cuttings easily take root. Simply remove the lowest leaves, stick the bottom inch of the cut stem into a pot of new potting soil, water it in, cover the pot and cutting with a plastic baggie, and put it on a windowsill for 3 weeks. You can opt to use rooting hormone to speed up the rooting process if you want, but it’s not necessary. When 3 weeks have passed, remove the baggie and you have yourself a new mint plant for growing indoors. You can also root mint in water, which is discussed in a later section.
The basics of how to grow mint indoors
To maximize the growth of your indoor mint plant, you’ll need to provide it with a few things.
- Sunlight: Mint requires a very bright indoor location. Outdoors, mint can tolerate a good bit of shade. But inside, the more light, the better. Otherwise, the plant will stretch for the light and become leggy and pale. If you don’t have a sunny, north-facing window that receives sun through the better part of the day, consider purchasing a small grow light to install over your mint plant.
- Water: One of the most straightforward factors to consider when learning how to grow mint indoors is watering. Unlike some other herbs and houseplants, mint is far from demanding. Yes, you can over- or under-water it, but neither is easy to do. Mint tolerates both “wet feet” and dry soils. However, I aim for a good balance between the two. Water the plant only when the soil feels dry to the touch and the pot is light. To water indoor mint plants, move the pot to the sink or bathtub, turn on the water, and let it flush through the soil and exit the drainage hole in the bottom of the pot. I flush water through the pot three or four times, let it drain fully, then return the pot to its spot on the windowsill.
Fertilizing indoor mint
This is another easy task when it comes to growing mint indoors. From mid-spring through late summer, fertilize your indoor mint plant every three weeks with a liquid organic fertilizer. Mix it according to label instructions. If you plan to harvest from your plant all winter long, from early fall through early spring fertilize once every six weeks. Unlike other houseplants, indoor mint will still be actively growing through the winter months, so feeding it is a good idea. Just don’t overdo it.
How to prune indoor mint plants
Regular “haircuts” are necessary to keep your mint plant bushy and to encourage new growth. Use a pair of herb scissors or needle-nose pruners to trim the stems back on a regular basis, ideally once every few weeks. Make the cut just above a set of leaves and two new stems will develop from the leaf nodes, causing each stem to branch in two. Use the trimmings in the kitchen.
Three ways to grow mint indoors
There are three primary ways to grow mint as a houseplant. Let’s discuss each option in turn.
1. How to grow mint indoors – in soil
This is the most familiar way to grow mint inside. Choose a pot that’s at least 8 inches in diameter and has a drainage hole in the bottom. I like decorative ceramic pots, but plastic works too. Avoid clay pots because they dry out too quickly. Use a high-quality, general potting soil to pot your mint plant, making sure to leave about a half inch of head space between the top of the soil and the rim of the pot. This acts as a reservoir and keeps irrigation water from running off too quickly. Potted mint plants can live for years as houseplants.
2. How to grow mint indoors – in water
Mint can also be grown indoors in water. The main benefit of this method is the lack of soil. No mess, no watering, and never any fungus gnats. However, mint doesn’t live forever in water. Eventually the leaves will yellow and the plant will stop growing. However, keeping a few water-rooted stems in a jar above the sink means you’ll be able to make the occasional harvest. To start growing mint indoors in water, simply take some stem cuttings from a mother plant, remove all the lower leaves, and prop the stems in a glass of water. Change the water and wash the glass every five to seven days. They will quickly develop roots and can be grown in the water-filled jar for a few weeks or months, depending on the growing conditions.
3. How to grow mint indoors – hydroponically
It’s also possible to learn how to grow mind indoors by using hydroponics. In fact, mint is a great crop to grow using a commercially made or a DIY hydroponic system. The lack of soil definitely translates to less mess, but hydroponic systems are more expensive than soil-based growing. The nutrient solutions are more costly than traditional fertilizers, too. However, if you plan to grow a lot of mint, hydroponics is worth researching. For some excellent inexpensive DIY hydroponic options and more info on this growing method, I recommend the book DIY Hydroponic Gardens by Tyler Baras.
Best types of mint for indoor growing
You can grow any type of mint indoors. Try peppermint (Mentha x piperita), spearmint (M. spicata), pineapple mint (M. suaveolens ‘Variegata’), chocolate mint (M. x piperita ‘Chocolate Mint’), and apple mint (M. suaveolens). Each offers its own flavor in addition to making a unique-looking houseplant. I love the variegated leaves of pineapple mint!
Harvesting mint indoors
To harvest your indoor mint plants, remove individual leaves as needed, or clip off entire stems for drying or fresh use. Don’t be afraid to cut the plant back substantially a few times a year. This encourages the production of flavorful new growth and encourages a bushy growth habit. I typically cut my plants back all the way to the soil in the mid-spring. This forces the production of all new deep green and flavorful leaves a few weeks later. It rejuvenates the plant just before its period of most active growth.