Herb · Lamiaceae
Spearmint
Mentha spicata
A sunlit pot of spearmint brings a fresh, green note to a kitchen and keeps the season's leaves close at hand.
Full sun
Every 2–4 days
59–77°F · 15–25°C
80–90 days
Overview
Spearmint is the quiet workhorse of a well-lived kitchen, the mint behind a jug of iced tea, a bowl of new potatoes, and a glass set out on a summer evening. Part of the mint family and a hardy perennial, it settles into a home for years, retreating in winter and returning each spring with a clean, cooling scent that reads as fresh and unfussy. Few plants feel this at ease in a lived-in space.
The one thing to plan for is its reach, since spearmint travels on underground runners that wander far past where you first set it. That habit makes it a natural for a pot of its own, a windowsill vessel, a sunken container by the back door, or a raised bed kept apart from everything else. Given that single boundary, it slips into a daily routine and asks for very little.
What keeps spearmint looking its best is the same thing that puts it to use: regular cutting. Snip the tips for the table and the plant stays low, full, and handsome on a sill or a bench, while leaving it uncut lets it stretch and lose its polish. Keep a pair of scissors nearby, harvest as you cook, and it stays good company from spring right up to the first hard frost.
Care
The short version: set spearmint in full sun or a little shade, keep the soil evenly moist rather than dry, and give it a container of its own so it stays where you want it. Snip the tips often and it holds a neat, welcoming shape.
Light
A sunny spot is where spearmint looks and tastes its best, staying compact and full of flavor on a bright sill or a south-facing step. It takes partial shade gracefully too, which suits a warm room or a shaded patio where midday sun would be too much.
Water
Keep the soil evenly moist and never let it go dry, since a thirsty plant quickly loses its fresh, full look. A drink every 2 to 4 days fits neatly into a daily routine, with a touch more in a heat wave or in a container on a warm sill, where moisture disappears fast.
Soil
A rich, loamy mix with plenty of organic matter keeps the roots happy and the leaves lush in a pot or a bed. Aim for a pH of 6.0 to 7.0, close to neutral, which most bagged potting soils already offer.
Temperature
Spearmint is content in the same comfortable range a home enjoys, 59°F and 77°F (15°C to 25°C), where it grows steadily. Left outdoors it simply rests over winter, dying back to the roots and reappearing in spring, so there is no drama in a cold season.
Humidity
Ordinary room air of 40% to 70% keeps the foliage looking its best. In a hot, dry room spider mites can move in, so a moist root zone and an occasional misting keep the plant fresh and presentable.
Feeding
A single feed of balanced fertilizer or compost in spring carries spearmint elegantly through the season. Keep the nitrogen light, though, because too much brings soft, floppy growth and dulls the clean flavor that makes the plant worth keeping close.
Pruning
Regular snipping keeps spearmint neat and full rather than tall and bare, and a hard cut back after flowering brings a fresh flush for the sill. Remove the flower spikes as they rise, since a stem that blooms trades its flavor for a bloom nobody planted it for.
Repotting
In a container, refresh spearmint every 1 to 2 years, or sooner once it turns rootbound, dividing the clump as you go. Roots winding around the pot edge, soil that dries almost at once, and smaller leaves are the plant's way of asking for a new home.
Size & spacing
Spearmint stays a modest 12 to 24 inches (30 to 60 cm) tall, but it reaches wider, spreading 24 to 35 inches (60 to 90 cm) across as the runners travel. Give it that width, or keep it in a container, so it sits well beside the other plants in a bed or on a bench.
When to plant
Hardy through zones 5 through 9, spearmint keeps its place in the garden year after year and returns each spring on its own. Move plants outdoors in spring once hard frost has passed, gather leaves across the whole season, and pinch off the summer flower spikes so the harvest stays sweet.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring (though division/cuttings are more reliable than seed)
- Plant: Spring, after danger of hard frost
- Harvest: Harvest leaves throughout the growing season; pinch off flower spikes in summer to preserve leaf quality
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Spearmint is an easy houseguest, so its few problems come down to a leaf disease, a hot-weather pest or two, and its tendency to overstay its welcome and spread. Match what you see below and step in early, while the fix is still a small one.
Rusty orange freckles spoiling the undersides of leaves
Those freckles are mint rust, a fungus that settles in when foliage stays damp and crowded, and it quickly tarnishes a good-looking plant. Pick off the marked leaves and bin them rather than composting, then open the plant up so air can move freely. A badly spotted clump can be cut right to the ground and will return clean and presentable.
Fix:
- Remove and destroy infected foliage (do not compost)
- Improve air circulation by thinning crowded growth
- Avoid overhead watering to keep foliage dry
- Cut back severely affected plants to ground level
Dull, speckled leaves with a fine webbing beneath
A tired, dusty look with fine webbing points to spider mites, which arrive on hot, dry air and drain the color from the leaves. A firm rinse under water knocks them back, and keeping the soil moist with the humidity up makes the plant an uninviting place to settle. Insecticidal soap clears a heavy case and restores the fresh look.
Fix:
- Rinse foliage with a strong spray of water
- Raise humidity and keep soil moist
- Apply insecticidal soap if severe
Mint drifting out and crowding the rest of the bed
Spearmint spreads on underground runners that surface as new shoots well beyond where it started, and unchecked it will crowd out its neighbors. The tidiest answer is to grow it in a sunken bottomless pot or a bed of its own, or to sink a root barrier at least 30 cm deep. Lift any stray runner before it roots and the planting stays composed.
Fix:
- Grow in a buried bottomless container or dedicated bed
- Sink physical root barriers 30+ cm deep
- Dig out and remove escaped runners promptly
A tired clump with smaller leaves and less life
An older planting fills with tangled roots and runners until the middle fades and the leaves grow small and sparse. Lift it, separate the healthy outer pieces, replant them in fresh soil, and discard the woody center for a plant that looks alive again. A division every two to three years keeps it fresh and worth its place.
Fix:
- Divide the clump and replant healthy sections
- Refresh soil and discard the woody center
Toxicity
At the table spearmint is a friend, a herb people have cooked with for generations. The one thing to keep in mind is its essential oils, which can leave cats, dogs, and horses with a mild stomach upset if they eat a large amount, so a whole plant is best set out of a grazing pet's reach.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A cat that samples a leaf or two comes to no harm, but a large mouthful of the oily foliage can bring on drooling, vomiting, and loose stools.
Dogs Mild
A dog that works through a good pile of leaves may end up with an upset stomach, a little vomiting, and diarrhea that soon passes.
Horses Mild
A horse grazing a large amount can pick up a mild bellyache and soft droppings from the concentrated oils.
Rabbits Caution
A few leaves now and then suit a rabbit fine, but the strong oils mean it should not make a meal of spearmint.
Livestock Caution
Goats, sheep, and cattle rarely go looking for mint, and a casual browse does little harm, though a gut full of it loosens digestion.
Birds Caution
Most birds pass over the pungent leaves, so offer only a token amount, since the oils are stronger than a small body wants.
People Safe
For people spearmint is a treasured kitchen herb, safe in teas, sauces, and salads at the everyday amounts a cook reaches for.
Normal culinary amounts of spearmint leaf used in food are not a concern; the risk relates to ingestion of large quantities of the plant or concentrated essential oils.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
The plain species dresses a kitchen beautifully, but a couple of named types are worth seeking out when you want a little more flavor or a more decorative leaf on the sill.
Mentha spicata 'Kentucky Colonel'
Large, crinkled leaves and an unusually strong spearmint flavor make it the classic choice for a mint julep and for a well-stocked kitchen.
Mentha spicata var. crispa (Curly mint)
Tightly ruffled, curled leaf edges lend it a decorative, frilly look that dresses up a windowsill while keeping the clean, familiar spearmint scent.
How to propagate
Spearmint is among the easiest plants to share, and most people pass it along not by seed but by splitting a clump or rooting a simple cutting for a friend.
DivisionEasy
Spring or autumn · 2 to 4 weeks
Dividing a clump is the most reliable way to grow your spearmint collection or pass some to a friend. In spring or autumn, lift an established plant and separate it into sections that each keep a length of runner with its own roots and shoots, then settle them into fresh pots or ground. Each piece finds its feet within 2 to 4 weeks.
Stem cuttingsEasy
Spring through summer · 1 to 2 weeks
Rooting a cutting is almost effortless and perfect for filling a spare vessel on the sill. Any time from spring through summer, snip a healthy stem tip and stand it in a glass of water or press it into moist soil, and roots appear within 1 to 2 weeks, ready for a pot of its own.
Myths
Mint must be harmless in the garden because it is just a small herb.
A modest size says nothing about how it behaves in a bed. Spearmint travels underground and can take over a whole planting in a season or two, so the graceful move is to keep it in a buried pot or behind a root barrier rather than loose among your other plants.