Everything You Need To Know About Growing Spearmint From Seed [Full Guide]

Spearmint is such a great and useful herb to grow in your kitchen or garden. There are almost endless ways to use spearmint to make your life easier and more enjoyable. From cooking, ridding your garden of pests, making your home smell nice, or ridding you of that annoying headache, spearmint can do it all.

Many people buy a juvenile mint plant straight from the store and simply take care of it from there. Sure, that’s a great way to get mint if you don’t have the time to grow your own. But, I think you’ll find that it’s much more rewarding growing your spearmint straight from the seed.

Many people shy away from growing their plants from seeds because it can be tricky and time consuming. I won’t deny that it takes a bit more time to grow your spearmint from a seed, but it’s really not difficult at all.

Spearmint is a very hardy plant that can grow under almost any conditions. This includes growing from a seed. As long as you provide it with the right amount of light and moisture, your seeds will be sprouting in no time.

So, now that I’ve convinced you, I’m sure you’re wondering how to grow your spearmint from a seed. Don’t worry, I’ve included everything you need to know, below.

First, I cover why you may want to grow spearmint from seed then when to plant your spearmint seeds and where to get them from. I also discuss how to grow your seeds both in the garden or a pot and then what to do next to grow a healthy plant.

Why Grow Spearmint?

Spearmint has so many uses and many people love to grow it in their garden and kitchen. The main use of spearmint is for cooking. Spearmint is one of the most common mint varieties used in cooking because of its cool and refreshing flavor.

Besides it’s cool flavor, it also has a cool scent. Many people will dry the leaves and use them as potpourri around the house. The scent even acts as a great pest deterrent.

Also, if you’re feeling a headache or a bit of nausea coming on, brew yourself a cup of spearmint tea. The aroma is often helpful in alleviating the symptoms.

Why Start Growing Spearmint From Seed?

A good reason to grow your own spearmint plant seeds is so that you are a part of the entire growing process. If you buy the plant as a juvenile, then you won’t know what kind of soil it was grown in or if any pesticides were used.

The main reason people choose to grow their spearmint from seeds is because it’s cheaper. If you’re growing from a seed, it’s likely that you got the seeds from your own plant or from the plant of someone you know. Even if you buy seeds from the store, most seed packets cost less than one dollar.

If you want to plant your seeds outside and grow them outside, your timing is even more limited. Although spearmint is cold tolerant, it doesn’t handle frost well. You’ll need to wait until the last frost of spring before you plant your seeds.

Growing spearmint in a pot
Growing spearmint in a pot

How To Get Spearmint Seeds

Getting spearmint seeds is easy! You can go to almost any store to grab some seeds, or you can use an existing plant to harvest them.

From A Store

There are lots of stores where you can buy spearmint seeds in-person or online. Buying your seeds online gives you more options. Stores like Burpee, Eden Brothers, and True Leaf Market sell a wide variety of mint seeds, so they’ll certainly have spearmint.

If you’d rather look in-person, that’s okay too. Spearmint is a very common kind of mint and is easily found. Home improvement stores, grocery stores, and department stores are sure to have them.

How To Harvest Spearmint Seeds

Many people that already have spearmint plants will use the seeds from those plants to grow more. This is a cheap and effective way of using what you already have to grow more. Even if you don’t have a mint plant yet, you can do this if you know someone who does have one.

So, how do you harvest the seeds?

You need to have patience when it comes to harvesting because you’ll need to wait for the spearmint’s flowers to bloom. From there, you’re going to have to wait some more. We need the flowers to die before the seeds can be harvested.

When you notice the flowers dying, you’ll prune most of them off, but make sure you leave a few. After the remaining flowers have turned brown, you can prune those as well.

Next, you’ll place the dead flowers into a paper bag and leave the flowers to dry. This process will take about 2 weeks.

Then, you can remove the flowers from the bag and crush them gently with your fingers. Don’t be too rough or you may crush the seeds. Blow away any excess petals, and you have your seeds!

At this point, it’s too late in the season to grow the seeds outside. Either sow them inside, or store them for next year’s growing season. Be sure to put them in a labeled envelope and store them somewhere cool and dry.

When To Plant Spearmint Seeds

When you’re going to plant your seeds depends on whether you’re growing them inside or outside. It also depends on what climate you live in. If you live in a warm climate, you’ll have a much longer growing season than someone who lives where it’s frequently cold.

If you’re planning to grow your seeds inside, and keep them inside, you can begin growing at any time of year.

If you’re beginning your seeds inside, but want to plant them outside later, the timeframe is a bit different. You won’t want to plant your seedlings until after the last frost of spring, so you should plan your planting times accordingly.

If you want to move your seedlings outside in spring, then you should begin sowing your seeds 8-10 weeks before the last frost of spring.

However, spearmint is a very hardy plant, so you don’t have to plant it in spring. You can plant spearmint anytime between the last frost of spring and 2 months before the first frost of fall.

Exactly How To Grow Spearmint From Seed In The Garden

How to germinate spearmint seeds in the garden is a pretty simple process. There aren’t many steps you need to take to get your herb prepared to sprout.

First, you’re going to want to have prepared soil in the location that you want to plant the seeds. You’ll sow the seeds on top of this soil, being careful not to put the seeds into the soil.

After sprinkling the seeds on top of the soil, you’re going to cover them with a light layer of vermiculite. From there, you’re going to water your seeds. Make sure that you keep them watered and don’t allow the soil to completely dry out.

The soil should always remain moist, but it should never be so wet that it becomes soggy. After about 2 weeks, you’ll notice the spearmint seeds beginning to sprout.

Exactly How To Plant Spearmint Seeds In A Pot

There are more steps to growing spearmint in a pot, but it isn’t really more difficult.

The first thing you’re going to want to do is get something to grow the seeds in. I recommend using a seed flat, but some people like to sow their seeds in their own individual pots.

After you’ve picked where you want to plant your seeds, you’re going to put soil into the container. From there, you’ll sow the seeds into the soil about 1/4 inch deep.

If you’re using a seed flat, I recommend pre-separating the seeds. A seed injector is nifty for this. You can always let the seeds grow together, but you’ll need to separate the seedlings later.

Next, you’ll want to keep your container in a warm location with lots of sun. Always keep the soil moist, but never make it soggy.

Depending on the climate of your house, you may need to mist the seeds frequently. To better keep them moist, and to speed up the process, you can always use a container with a lid. Just be sure to remove the lid after the seeds begin to sprout.

You’ll continue to take care of your seeds and seedlings until they sprout two true leaves. At this point, they’re ready to be planted outside, and you can begin hardening them off.

Hardening off simply refers to the process of preparing the seedlings for the harsher outside conditions.

To start, place the seedlings outside where they’re sheltered and in the shade. People often use their porches for this purpose. You’ll leave the box outside for a few hours and then bring it in.

Do this every day for about a week. Each day, you’ll gradually increase the amount of time the seedlings spend outside. Never leave the seedlings outside overnight.

After the seedlings have spent a full day outside, you can repeat the process, but in a sunny area. Do exactly as I described above, but in a sunny area. After about a week of this, they’ll be ready to be planted into the ground.

What To Do Next?

Spearmint is a very hardy plant, but there are some things you can do to make your plant happier.

Temperature

Spearmint does best at cooler temperatures between 65-70 degrees Fahrenheit.

It is cold tolerant, so it also does very well in lower temperatures as long as it’s above freezing. Spearmint can also survive in hotter temperatures, but doesn’t do as well.

Sunlight

Spearmint likes to have a lot of light, but it doesn’t like it to be overbearing. Partial sun is best for spearmint. It can survive in direct sunlight, but you’ll need to do a lot more watering.

Read more about how much sun mint needs here.

Water

Like sunlight, spearmint loves water, but too much is not helpful. Water your spearmint so that it’s always moist, but not soggy. You’ll know when to water it when the top inch of the soil becomes dry.

Read more about how much to water spearmint here.

Fertilizer

Fertilizer isn’t needed for spearmint and can often be detrimental. You’ll only want to use fertilizer if you visibly notice your plant suffering due to a lack of nutrients.

Final Words

As you can see, it’s not difficult to grow spearmint from seeds. All the seeds need is a bit of attention and care. If you can give them that, you’ll have beautiful spearmint plants growing in no time.

Want to learn more? Click here to learn how to grow mint indoors or here to learn what to plant with spearmint. You can also find all my guides to growing spearmint and mint here.