Growing Spearmint is relatively easy but because it tends to be a vigorous grower, there are some precautions gardeners should take.
Growing spearmint requires nutrient-rich soil with a pH of 6.5 to 7. It tolerates full sun to partial shade and needs watering only when the top two inches of soil are dry. Gardeners may root spearmint cuttings in water when the plant is fully established. In zones 4 to 11, spearmint is a perennial.
In this article, we’ll answer the most common questions about growing spearmint and walk you through how to grow this herb outdoors or in a pot.
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Spearmint Growing Requirements
Growing spearmint is relatively easy — maintenance requirements involve watering and pruning, and not much else. In this section, we’ll cover the growing needs for this minty herb.
What Type of Soil Does Spearmint Prefer?
Spearmint prefers nutrient-rich, well-draining soil. However, it can grow in most types of soil. The ideal pH is between 6.5 and 7. Moisture is critical – in its native habitat, spearmint tends to grow near stream beds. Keep the soil moist by using a light-colored mulch around the base of the plant.
Read about how to identify and manage alkaline soil.
Does Spearmint Need Full Sun?
Spearmint tolerates full sun to partial shade. When placed in a particularly shady spot, however, spearmint tends to crawl towards the sunlight. Keep plants trimmed to avoid “legginess.” During the afternoon, plants should be protected from the sun, especially in southern growing regions.
When Should I Water Spearmint?
You should water spearmint when the top two inches (5.08 cm) of soil are dry – never let the plant dry out completely. Moisture is critical to the growth of spearmint. It can tolerate short periods without water, but long-term drought or lack of water proves fatal.
Can You Root Spearmint in Water?
When you trim spearmint, you can encourage the cuttings to grow new nodes by sticking them in water or moist soil. So, how do you root spearmint in water?
First, you’ll want to take your cuttings from a fully established, mature plant. Ensure that the plant is healthy and free of bugs, fungi, or other diseases.
Gather the cuttings in late spring or early summer before the plant flowers. Use sharp scissors or pruning shears and cut about 3 to 5 inches (7.62 to 12.7 cm) above the stem. Cut off the leaves from the bottom part of the stem.
Root spearmint in water by pouring about ½ inch (1.27 cm) of water into a small glass cup, jar, or vase. Place the cuttings in the container, ensuring that the plant stem is in contact with the water. Set the container in a well-lit area, like a window sill. Replace the water when it looks cloudy.
(Source: University of Florida)
Once the roots are a few inches long (after about two weeks), transplant the cuttings into a pot with a potting mix and fertilizer (please see the two “How To Grow Spearmint” sections at the end of this article for a more detailed explanation of what you should do).
Starting spearmint cuttings in water is easy, but there are some drawbacks. Rooting spearmint in water increases the risk that they’ll die during transplant. Going from water to soil can be quite a shock to the plant’s system, often making water-rooted spearmint weaker than soil-rooted plants.
Do Spearmint Plants Spread?
Spearmint spreads — and fast! This perennial can quickly take over a flower bed if left unchecked. Contain the roots by keeping the spearmint in a pot and sinking the pot into the dirt. Prune the plant as it grows and watch out for “crawlers.” The plant often sends stems out on the soil’s surface.
Does Spearmint Come Back Every Year?
Spearmint comes back every year and is a hardy perennial in USDA zones 3 to 11. It’s often the first plant to return in the spring. However, in warmer climates, spearmint grows year-round. Keep a close eye on it as it begins to grow and prune as necessary to prevent it from smothering your garden.
Because spearmint is a perennial and a fast grower, it’s an excellent plant to have around for making different household products, from homemade toothpaste to tea — it may even be dried out to use during the winter months while the plant is dormant (source).
How Do You Care for Potted Spearmint?
Caring for spearmint is easy. This low-maintenance plant requires little effort aside from the occasional watering and pruning.
Care for potted spearmint by watering it when the top two inches (5.08 cm) of soil are dry. Fertilize the plant with quality herb food (pellets or liquid) at least once a month. Every two years, divide the plants into new pots to keep them healthy and prevent them from getting root-bound.
We’ll cover more information regarding growing spearmint in pots in the next section.
How To Grow Spearmint in Pots
When growing spearmint in pots, it’s highly recommended that you start with a small plant. Pick one up from your local nursery or visit a shop specializing in herbs for best results.
Growing spearmint from seeds is possible, but germination tends to be inconsistent and unpredictable. If you decide to try your hand at seeds anyway, use a seed starter pot and ensure that they have plenty of warmth and sunlight until they germinate.
If you’re starting with a small spearmint plant, follow these directions to grow it in a pot successfully:
- Remove the spearmint plant from its current container. The container that your plant came in likely isn’t big enough to sustain it as it grows. To remove it, tilt the container and gently (but firmly) grasp the stem as close to the soil as possible. Move the stem back and forth until it’s out of the pot. Remove excess soil from the roots.
- Fill a pot that’s at least 10 inches (25.4 cm) in diameter with a quality potting mix. Ensure that there’s a drainage hole at the bottom of the pot. If you’re looking for potting mix, I recommend The Good Earth Organics Zen Blend Premium Potting Soil (link to Amazon). This starter soil is suitable for indoor and outdoor growing. It’s fast-draining and safe for cuttings and seedlings.
- Lightly sprinkle an herb fertilizer into the soil and mix it in. Jobe’s Organics Organic Plant Fertilizer (available on Amazon) is a great option. The 4 pound (1.81 kg) bag is sure to last until the growing season ends, and it’s an ideal choice for organic gardening.
- Make a hole in the soil to place the plant. Remove some of the soil with your hands, making a hole to fit the seedling. Set the soil aside. Place the seedling into the hole and cover the roots with the excess soil. Pat it gently at the top, but don’t compact it too much, as this reduces airflow.
- Give the spearmint a good soaking. Once the plant is transplanted, water it deeply. Make it a point to keep the soil moist until the plant’s roots are established, usually after two weeks or so. If the plant begins to wilt after a day or so, don’t fret. It’s likely in shock from the transplant and should recover.
- Put it in an area where it’ll receive six hours of sunlight per day. Spearmint plants can tolerate partial shade, but they won’t reach their maximum potential. Giving the plant at least six hours of indirect sunlight ensures that it’ll thrive.
- Water the spearmint when the top inch (2.5 cm) of potting soil feels dry. While spearmint can tolerate several days without water, they cannot withstand long periods of drought. It’s essential that you water the plant whenever the top couple inches of soil are dry. However, you may have to water more often if the weather is particularly hot and arid.
- Pinch off the tips of spearmint regularly. If you allow the tips of spearmint to grow out of control, the plant may appear spindly. Instead, pinch off the tops of the plants to promote full, lush growth. If needed, you can prune half of the plant – just cut the stem about an inch (2.5 cm) above the soil.
- Remove blooms as soon as they appear. Spearmint produces beautiful four-inch (10.6 cm) lavender flowers, but if you’re going to use the leaves for cosmetics or recipes, you’ll want to pinch off these blooms as soon as they appear. Once the spearmint plant flowers, the potency, and quality of the leaves are reduced.
- Fertilize the plant once a month. Use organic fertilizer to feed the spearmint at least once a month. This keeps the plant happy and healthy.
- Re-pot as the spearmint grows. As your spearmint gets larger, it’ll take up a lot of space in the pot. This can lead it to become rootbound. Every two years, you should divide potted spearmint to ensure there’s enough room to grow.
How To Grow Spearmint Outdoors
Growing spearmint outdoors is tricky, especially if you don’t want it growing all over your flower bed. To prevent this plant from overtaking your garden, you’ll have to be very particular about your spearmint planting methods.
- Plant the mint in a pot. Spearmint is a fast-growing plant and doesn’t hesitate to take up as much space as possible. This means you’ll want to plant the spearmint in a pot and place the pot in the ground to contain its roots. Ensure that this pot has plenty of drainage holes.
- Choose an ideal location. Spearmint grows about one to two feet (30.48 to 60.96 cm) tall and equally as wide. Choose a location where it won’t shade other plants (unless those plants like shade) but still receives full sun or partial shade.
- Space the plants about 18 to 24 inches (45.72 to 60.96 cm) apart. As mentioned in the previous steps, spearmint plants tend to be tall and wide. Keep them spaced apart for best results. Dig a hole slightly bigger than the diameter and depth of the pot.
- Sink the pot into the hole. Place the entire pot into the hole. Planting the spearmint underground in a pot gives you the benefit of enjoying the lush, bushy plant in your flower bed without having to worry about it stealing nutrients and space from your other plants.
- Fill in any gaps with potting soil. Once you’ve placed the pot in the ground, fill in any gaps with potting soil and cover the top rim of the pot to hide it.
- Use a light mulch. Add a layer of light mulch to the spearmint plant. Not only does this help keep the soil moist and cool, but it also prevents water from splashing up on the leaves during rain.
- Prune your plant. As your plant grows, prune it to prevent it from appearing spindly and leggy. Pinching the top leaves off every now and then ensures that the plant will grow bushy and thick.
- Water the spearmint. Give the spearmint a good soaking whenever the top few inches (2.5 cm) of soil are dry to the touch. If you can pinch the soil in your fingers and it holds its shape, it doesn’t need water. If it simply crumbles, it’s time for soaking.
- Feed the plant. About once a month, treat your spearmint to a high-quality fertilizer to keep it looking strong and healthy.
Spearmint plants are a beautiful addition to any garden – they can line walkways or act as decorative pieces for other vibrant flowers. In addition to its visual appeal, spearmint has many practical applications as well. It may be used in tea, recipes, cosmetics, potpourri, or even for skin ailments. The downside, however, is that spearmint spreads – and it spreads fast!
Fortunately, caring for spearmint and containing its roots isn’t difficult. With a little effort on your part (and very little maintenance afterward), you’ll have a happy, thriving spearmint plant that won’t overtake your flower bed.
Learn what to plant with Spearmint using our guide on Herbs that grow well together.