Exactly How To Grow Mint Indoors From Seed [Full Guide]

Mint is one of the most popular herbs used in both kitchens and gardens. It can be used for so many things. It’ll make your cooking taste better, it will make your home smell better, and it will help your headache to feel better.

But why should you grow it indoors, and why is it better to start from a seed?

We’re going to cover these questions here. But rest assured, if you’re ready to start your journey of growing mint seeds inside, you’re in the right place. I cover exactly how to get your mint seeds, plant them and then grow them into a healthy mint plant.

Why Grow Mint?

Having mint, especially indoors, is great. Mint can be used for a number of things like cooking, making your home smell wonderful, and for use in aiding minor ailments.

If you grow your own mint, you’ll always have some of the fresh herb available. Buying fresh mint at the grocery store can quickly add up, so why wouldn’t you avoid all that and grow it yourself?

Better yet, if you grow your mint inside instead of outside, it’ll be available for use all year round.

Can You Grow Mint Indoors?

Mint can be grown indoors, and some people argue that it’s better to grow mint indoors than outdoors.

The great thing about growing mint inside is that you can use it throughout the entire year. Usually, if you live somewhere where it often gets below freezing over winter, there will be several months where you’ll be unable to use your mint plant if it’s outside.

Another great reason to grow your mint inside is because it’s easier to contain. The one thing that mint is known for is its fast growing speed. Mint can grow at up to 4 inches a month, and it never stops. That is, unless you do something to stop it. Sure, you can set up barriers in your garden to keep it from spreading, but keeping it in a pot inside is much simpler.

One downside to growing mint indoors is that you need to keep a closer eye on it. Less soil means that that soil will dry out quicker. You may find yourself watering your plant more often when it’s inside.

Is Mint Easy To Grow Indoors From Seeds?

It is very easy to grow mint indoors, even from a seed. Mint is a hardy herb, so it’s almost impossible to kill it.

This hardiness starts as a seed, and you will find that they sprout very easily. To get your mint seeds to sprout, all you need is a container, some moisture and humidity, some light, and some patience.

With just those four things, you’ll notice your mint seedlings beginning to crop up in just 2 weeks.

Growing mint in a pot
Growing mint in a pot

How To Get Mint Seeds

It’s super easy to get mint seeds. Mint is one of the most popular kinds of herbs on the market. You can easily find the seeds online or at a local store. Or, if you or someone you know already has a mint plant, you can harvest the seeds for free!

If you’re looking for a bit of variety in your mint plants, an online store might be the way to go. Stores like Burpee, Eden Brothers, and True Leaf Market have a wide variety of mint plants.

If you’re looking for something more common, like spearmint or peppermint, you can probably stick to a local store. Grocery stores, home improvement stores, and even farmers markets are likely to have fresh mint seeds.

Harvesting is a longer process and is more complicated than buying seeds from the store. However, it aids in the whole growing process. Best of all, it’s free, and it’s a great way to utilize an existing plant.

If you need help on how to harvest seeds from your mint plant, here are some instructions.

You’ll need to wait until the flowers bloom on your mint plant. The flowers are where you’ll find the seeds, so this step is essential. After the flowers bloom, you’ll need to wait through the season until the flowers begin to die out.

  1. As the flowers begin to die, you can prune them off
    • be sure to leave a few flowers intact — these are the flowers you’ll use to harvest the seeds
  2. Wait until the remaining flowers turn completely brown and prune them
  3. Place the flowers into a paper bag
  4. Place the bag in a cool dry place for the flowers to dry for about 2 weeks
  5. After 2 weeks, remove the dried flowers from the bag
  6. Gently crush the flowers with your fingers to expose the seeds
  7. Remove any leftover petals

After harvesting the seeds, you can do one of two things: you can plant them right away, or you can save them for later.

Because mint seeds must be harvested at the end of the growing season, most people set the seeds aside for next year. However, because you’re growing your mint inside, you can begin the process whenever you like.

Can You Plant Mint Seeds At Any Time Of Year Indoors?

Absolutely! Most people strive to keep the inside climate of their home steady throughout the year.

Because of this, your mint plant will have no way of knowing what time of year it is outside. As long as it is warm inside and you provide it with the care it needs, your mint plant will grow.

The mint will not go dormant over the winter season like it would outside.

Growing Conditions For Growing Mint Indoors

Mint is a very hardy plant, and it needs much of the same care indoors as it does outdoors. There are a few things you should keep in mind, though:

Sunlight: Mint can survive in full sun, but it’s not recommended, especially indoors. Ideally, mint should be placed in partial shade. If you place it in full sun, you’ll have to water it more — something you already have to do just because you’re keeping it inside.

Ideally, keep your mint near a window where it gets lots of light, but not too much.

Read more about how much sun mint needs here.

Soil: The main thing you need to know is to pick soil that is well draining. The soil should also be rich in nutrients with a slightly acidic to neutral pH.

Water: Mint needs to stay moist at all times, but should not be waterlogged. In a pot, the soil will dry out quicker than it would outside. Because of this, you’re likely going to have to water your mint more frequently. Just be careful not to do it too much. Soggy soil can lead to root rot.

As a guide, check the soil by touching it. If it is dry about an inch down, it’s time to water.

Read more about how much water mint needs here.

Temperature & Humidity: Mint is cold tolerant, but the best temperature to grow it in is 65-70 degrees Fahrenheit. This means that most homes are already at an ideal temperature to grow mint.

Mint also needs plenty of humidity and will struggle when the humidity is too low. If your house tends to be dry, you’ll likely need to mist it throughout the day.

Fertilizer: Fertilizer isn’t usually necessary for mint and can sometimes cause more harm than good. However, when kept in a pot, the nutrients are depleted more quickly than outside.

If you notice your mint going through symptoms of nutrient withdrawal, you may need to invest in fertilizer.

What You Need For Growing Mint Indoors

What you’re going to need to grow your mint indoors is similar to what you would need to grow it outside. The most important thing for mint growth is plenty of sunlight and water, and we covered that above.

Here are some other things I recommend:

  • Well-draining soil
  • Pots of multiple sizes
    • You’ll want to start small as a seedling, but your mint will quickly outgrow that original pot
    • Mint will stop growing at whatever size pot you choose
      • If you want your mint to grow large, you’ll frequently need to repot your mint. Repotting about once a year should be sufficient
  • A window or a grow light
  • A misting spray bottle
  • A small watering can

Exactly How To Grow Mint From Seed Indoors

Growing mint indoors is super easy. Your plants are never going outside, so you never have to worry about “hardening” them for harsher conditions. Where they grow up is where they’re going to live. That means less stress on the plant’s part, and on your part.

If you’ve ever wondered how to plant mint seeds indoors, simply follow these steps:

  1. Prepare your growing container
    • Some people like to use individual pots. This is a good idea if you’re only only growing one or two plants.
    • Other people like to use seed flats. This method is best if you’re planning to grow multiple plants.
    • Once you’ve chosen your container, layer it with some prepared soil
  2. Sow your seeds about 1/4 inch deep into the soil
    • If you’re planting more than one seed, I recommend using a seed injector
    • Using a seed injector to separate the seeds is easier than separating the seedlings when they get bigger
  3. Keep the container in a warm location
  4. Keep the soil moist, but not soggy
    • I recommend using a lid over your container. This will keep the moisture in and keep the humidity high. If you don’t have a lid, you can always use plastic wrap.
    • Be sure to remove the lid or plastic wrap after the seeds begin to sprout
  5. You will notice the seeds beginning to sprout in about 2 weeks

What To Do Next When Growing Mint Indoors From Seed?

As your seedling grows, you’ll just continue following the guidelines I gave you above. Repot your mint at least once a year if you want it to get bigger.

Most importantly, make sure it’s getting the light, water, and nutrients it needs.

When And How To Harvest Your Indoor Mint

Because you’re growing your mint from seed, it’s important to know that you shouldn’t harvest too soon. Harvesting from a plant that is too young can irreversibly damage it. Instead, you’ll want to wait until your plant is at least 2 months old.

If it’s ready to be harvested, the stems will be about 6-8 inches long.

Because you’re growing your mint indoors, you can harvest at any time of year.

Be sure to never harvest more than 1/3 of the plant at once or the stems and leaves may not grow back properly.

You can either pick the leaves individually, or you can prune a whole stem from the plant. The choice is yours, but regular pruning will help keep your plant healthy.

Final Words

Growing your mint seeds indoors is a very easy way to make sure that you have fresh mint for years to come.

If you continue to grow your mint indoors, even better. Keeping mint in your house rather than your garden means that you’ll always have access to fresh mint year round.

Whichever you choose — inside or outside — your mint plant will prove very useful.

Want to learn more? Click here to learn how to grow spearmint from seed or here to learn how to grow mint outside. You can also find all my guides to growing mint here.