If you are looking for something a little different to add to your herb garden, look no further than chocolate mint. A hybrid plant produced by crossing peppermint with Mentha Citrata or orange mint, this is an attractive cultivar that tastes of orange and smells of chocolate.
What is Chocolate Mint?
A herbaceous perennial in USDA zones 5a to 9a, this plant is usually cultivated as an annual plant in colder climates.
Chocolate mint is darker in color than the bright green peppermint plant. Its round, lance-shaped, deep green leaves have purple undersides. The stems are also purple.
During the late spring and summer, lavender-colored flowers emerge. These attract scores of bees and butterflies to your garden.
A mature chocolate mint plant is roughly 2 ft tall. It spreads as far as it can. Like other types of mint, the chocolate variety spreads through the ground via rhizomes. Planting in a pot helps to contain this spread, preventing it from slowly overtaking your garden.
A hybrid plant, this is a sterile mentha plant. This means that the plant doesn’t produce seeds. Instead, it is propagated by taking stem cuttings.
Where to Buy Chocolate Mint
A sterile plant, you can’t grow this herb from seed. If you don’t have access to a plant from which you can take cuttings, you will need to purchase a chocolate plant from a garden store or nursery.
Where Can I Grow the Plant?
Chocolate mint is best planted in humus-rich, moist soil that is either neutral or slightly acidic. While these plants thrive in rich soils, growing in soil that is not so rich helps to concentrate the plant’s essential oils.
Avoid planting in sandy soils that are quick to dry out. These can lead to you having to water the plant more frequently.
Top dress the soil with organic matter once a year to keep it rich and maintain drainage.
These are one of the few herbs that prefer to grow in partial shade. Of course, you can also grow the plants in full sun, but you will need to water the plants more often.
Chocolate mint isn’t fussy about temperatures and tolerates all climates within its USDA hardiness range. However, plants in highly humid areas are prone to developing fungal diseases.
If growing in the ground, space the plants roughly 2 ft apart.
While chocolate mint is less aggressive than other varieties of mentha plant, it can still spread throughout your garden. To prevent this, either plant in pots or, if you want to add the plant to a herb garden, sink a bottomless bucket in the ground and plant inside. This should contain the spread of the plant.
Can I Grow Chocolate Mint Indoors?
Growing these plants indoors is possible, but the plants require lots of light and some humidity to flourish.
The plants are best placed in a sunny, south-facing window where they can receive at least 5 hours of light every day. Ideally, your chocolate mint plant will be able to bask in up to 14 hours of sunlight every day.
Exposure to lots of light helps to improve the color and flavor of the leaves. If you struggle to provide enough natural light, grow lights can be used to supplement natural light levels.
One of the easiest ways to raise humidity levels is to mist the plant’s foliage. However, this can leave the plants prone to developing powdery mildew. Instead, place the plants on a 9GreenBox Humidity Tray or saucer filled with pebbles and water. As the water evaporates, it raises the humidity levels around the plants. Just make sure that the pot isn’t touching the water.
How to Plant
To plant chocolate mint, remove the plant from its pot. Squeezing the sides of the pot loosens the soil and enables you to ease the plant out without damaging its roots.
Make a hole in the soil large enough to hold the plant’s root system. When placed in the hole, the top of the root system should sit just below the soil level.
If you are planting in a pot, your pot should be clean and have plenty of drainage holes in the bottom. When repotting, transplant into a similar-sized or slightly larger pot.
Fill the pot with fresh potting soil and plant to the same depth as in the previous pot.
After positioning the plant, fill the hole with fresh soil, firm down and water well.
Caring for Chocolate Mint
Like other types of mint, this is a quick-growing, low-maintenance plant.
This plant enjoys two growth phases during the year. The first is during the spring. Here the plant produces lots of upright growth and the second is after flowering. This second phase sees growth spreading horizontally via runners and offshoots of rhizomes. You can harvest the plant’s flavor-filled leaves during either of these spells.
When to Water
Chocolate mint is a thirsty plant. A healthy, growing plant requires 1 to 2 inches of water a week.
Water regularly, particularly during warm or sunny spells. While you can use a soil moisture sensor to work out when to water, I prefer to stick my finger into the soil. There is no need to water if the soil is cool or moist. On the other hand, if the soil feels dry, I know it is time to water my plants.
Be careful not to overwater your plants. This can lead to root rot developing.
Do I Need to Fertilize?
Despite their vigorous growth habit, chocolate mint plants don’t require lots of fertilizer. A dose of balanced fertilizer in the spring is enough to sustain its growth for the season.
How to Prune
Regularly pruning your chocolate mint helps to contain its spread. You can start pruning the leaves or stems when the plants are 4 to 5 inches tall. A mature plant can be pruned 3 to 4 times during the growing season.
Don’t prune more than one-third of the leaves at any time.
Use clean, sharp garden scissors to make clean cuts as you prune.
If you are growing your chocolate mint for its leaves, cut the flower buds away as they form.
Legginess, overly long stems that are sparsely covered in leaves, is often a sign that your plant needs more light. However, it can also signify that the plant needs to be pruned. If you suspect this is the case, cut the plant back by one-third. The leaves that emerge after pruning should be larger and the stems more densely covered.
In USDA planting zones 3 to 5, you can overwinter chocolate mint in pots outside. Cover the soil around the plant with a thick layer of coarse mulch such as straw or shredded wood. This insulates the roots, protecting them from cold winter temperatures.
You can overwinter your plants in colder areas simply by moving the pots into an unheated garage or basement. Regularly check your overwintering plants, watering when the top few inches of soil are dry. Once the last frost of spring has passed, the pots can be returned to their usual position.
Should I Let My Plants Flower?
Chocolate mint plants set flowers in the spring or early summer as the temperature rises. The plant’s small lavender-colored blooms attract lots of bees and pollinators.
To encourage flowering, feed the plant with a balanced fertilizer. Plants may be reluctant to flower if they are sitting in a pot that is too small. To rectify this, replant in a new pot that is 2 to 3 inches larger than the old pot.
If you are growing chocolate mint as a herb, cut the buds from the plat before they flower. Allowing your chocolate mint to flower harms the flavor of the leaves.
How to Propagate Chocolate Mint
The chocolate mint plant has a lifespan of 5 to 10 years. Learning how to propagate the plants ensures that you can continue growing the plants for far longer. Propagation is also a useful way to get new plants, either for yourself or friends and family, for free.
Chocolate mint is sterile. This means that it doesn’t produce seeds. Instead, you can propagate the plants by taking stem cuttings. This is easily done while pruning the plant.
Use sterile or clean garden scissors to cut a 3 to 5 inch healthy stem from the plant. Aim to make your incision just below a node; this is a point where a leaf grows from the stem.
Remove leaves from the lower third to half of the stem to create nodes. Through these nodes, new roots will emerge.
You can either plant the cutting in a small pot filled with fresh potting soil immediately or place it in a jar of water for a few weeks until roots develop. Make sure the newly created nodes are fully submerged. Change the water every few days.
Once roots form, you can plant the cutting.
How to Harvest
You can start harvesting the plants when they are 4 to 5 inches tall.
Never harvest more than two-thirds of the plant in one go. As we have already noted, regular pruning encourages more growth to form. However, pruning too severely can discourage growth. Regular pruning also helps the plant to maintain its flavor and aroma.
To harvest, use sharp garden scissors to cut the leaves of stems from the plant.
Prune your mentha plants by cutting the stems.
Preserving Your Harvest
Best used fresh chocolate mint leaves retain much flavor and aroma after being dried or frozen. Freshly cut sections keep in the refrigerator for around four days.
Like other fresh herbs, bundles can be dried by hanging the stems upside down in a warm, dry place out of the glare of direct sunlight. After drying, the leaves can be placed in a glass, airtight Mason Jar.
You can also freeze the leaves. To do this, lay the leaves flat on a baking tray and place them in the freezer until crisp. Once frozen, the leaves can be placed in sealable freezer bags and stored flat in the freezer. Alternatively, dice the leaves and mix them with either oil or water in an ice cube tray.
Chocolate Mint Pests and Problems
Like other mentha plants, this is a prolific specimen that happily grows in a range of different conditions.
Mint rust is a fungal disease that causes small orange spots to form on the undersides of leaves. Allow the leaves to dry out between waterings and ensure your plants are correctly spaced. Rust can be treated with regular applications of Earth’s Ally Organic Fungicide.
Check the foliage regularly for signs of disease.
Adopting good growing practices, such as correctly spacing out your plants and watering the soil so the leaves are not wet, helps prevent most issues.
Wilting or browning leaves are a sign that your plant is not getting enough water. You may need to repot the plant if it is in a pot or container.
Plants that sit in pots too small for their root system struggle to harvest enough moisture and nutrients to support healthy growth. The easiest way to check if your plant has outgrown its pot is to pick it up and see if roots are growing out of the drainage holes. Roots protruding from the bottom of the pot are a sure sign that your plant is too big for its home.
Repotting your plants every few years helps to maintain healthy growth. After repotting your chocolate mint plant, water well and apply a dose of balanced fertilizer.
Yellowing foliage, or leaves becoming droopy, can be a sign of overwatering. Check the soil around your plant. While these plants like a regular drink of water, it doesn’t want to have constantly wet feet.
If your soil is wet, lift the plant and check the roots. If they have started to turn dark brown and have a mushy, rotting texture, fungal root rot is already developing.
If you catch root rot early enough, cut away the blackened root sections and repot the plant in a clean pot filled with fresh soil. Dip the roots in a fungicide solution before planting. Otherwise, you will need to take cuttings and start again with a new plant.
Leggy stems with few leaves usually indicate the plant is not getting enough sun. Moving the plant to a sunnier position should rectify the issue. In addition, pruning your chocolate mint plant stimulates new leaf growth, making your plant bushier.
If light isn’t a problem, legginess can be caused by applying too much nitrogen-rich fertilizer. Switch to a more balanced product and prune the plant. Finally, leggy growth may indicate that the plant is outgrowing its pot.
Chocolate mint is an excellent choice if you are looking for something a little different to plant in your herb garden. Easy to grow, why not add this fascinating herb to your garden?
Jen is a master gardener, interior designer and home improvement expert. She has completed many home improvement, decor and remodeling projects with her family over the past 10 years on their 4,500 sf Victorian house. She is also a passionate farmer who keeps goats, chickens, turkeys cows and pigs on her farm, and an instructor for her community’s Organic and Sustainable Farming project.