Herb · Lamiaceae
Mint
Mentha spicata
Give it steady moisture and a pot to call home, and mint hands you fresh leaves from spring to frost.
Partial shade
Every 2–4 days
59–77°F · 15–25°C
80–90 days
Overview
Mint is one of the easiest herbs you can grow, which is both its charm and its catch. It belongs to the Lamiaceae family, the same square-stemmed tribe as basil and sage, and the most common garden kind is spearmint. Crush a leaf and the cool, sweet scent tells you at once what you're holding.
What sets mint apart is how it travels. It throws out runners above and below the soil, and each one roots and starts a new plant, so a single sprig can fill a bed in a season. That vigor makes it nearly impossible to kill, and it's exactly why most gardeners grow it in a pot or a sunken, bottomless container rather than turning it loose.
Beyond the kitchen, mint earns its place fast. It's a hardy perennial that comes back year after year in cool and mild climates, it shrugs off neglect, and a few leaves brighten tea, salads, and summer drinks. Give it damp soil and a little shade and it asks for almost nothing else.
Care
The short version: mint wants part shade and rich, steady-moist soil, a pinch back through the season to keep it bushy, and a container or edged bed to stop the runners from taking over.
Light
Mint does best in partial shade, especially where summers run hot, though it handles full sun if you keep the soil moist. A spot with morning light and some afternoon cover gives you tender, full-flavored leaves.
Water
Keep the soil consistently moist and never let the root zone dry out, since mint wilts fast when thirsty. In warm weather or a pot that means watering every 2 to 4 days, more if the leaves start to droop.
Soil
Plant in rich, moist, well-draining loam with plenty of organic matter worked in. A pH from 6.0 to 7.0 suits it well, which covers most ordinary garden soil.
Temperature
Mint grows best between 59°F and 77°F (15°C to 25°C), the cool-to-mild range it came from. It tolerates heat with enough water but slows down and toughens its leaves when things get too hot.
Humidity
Average humidity around 40% to 70% keeps mint happy, and outdoor air usually sits right in that band. Dry indoor air invites spider mites, so a contained pot benefits from a little extra moisture nearby.
Feeding
Mint needs very little feeding. A balanced all-purpose fertilizer or a light topping of compost in spring is plenty for the whole season, and overfeeding only thins out the flavor.
Pruning
Pinch the growing tips often to keep the plant bushy and to harvest as you go. Snip off flower spikes as they appear so the leaves keep their best taste, and cut the whole plant back hard after it flowers to push out fresh tender growth.
Repotting
A potted mint fills with roots and runners fast, so divide and repot it once a year or whenever the container is packed. Drop the woody center, keep the vigorous outer pieces, and start them in fresh soil.
Size & spacing
Mint stands 12 to 35 inches (30 to 90 cm) tall and spreads 2 to 4 feet (60 to 120 cm) wide, often wider if nothing stops the runners. Give it real room, or better still a container, so it doesn't crowd its neighbors.
When to plant
Mint shrugs off cold once it's growing, but young plants want a settled spring. Start seed indoors 6 to 8 weeks before the last frost, set plants out after the hard frosts pass, and then pick leaves right through the growing season.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6-8 weeks before last spring frost
- Plant: Spring, after danger of hard frost has passed
- Harvest: Harvest leaves throughout the growing season; pinch off flower spikes for the best leaf flavor
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Mint is tough, so most of its troubles come down to wet, crowded leaves, hot dry spells, or the plant simply outgrowing its space. Match what you see below and act early, while a quick fix still does the job.
Orange-brown pustules on the leaf undersides
This is mint rust, a fungus that takes hold when foliage stays wet and air can't move through the plant. Strip off and bin the infected leaves rather than composting them, thin the growth so it dries faster, and water at the soil line. In a bad year, cut the whole plant to the ground and clear the debris.
Fix:
- Remove and destroy infected foliage (do not compost)
- Improve air circulation by thinning growth
- Avoid overhead watering and keep foliage dry
- Cut affected plants to the ground and dispose of debris in severe cases
Mint marching out and swallowing the bed
This is mint being mint. It travels by underground and surface runners and will colonize a bed in a season if you let it. Trace stray shoots back to the runner and dig them out, then keep the plant in a sunken bottomless pot or a deeply edged bed so the runners hit a wall.
Fix:
- Dig out and sever stray runners
- Grow mint in a sunken bottomless pot or contained bed to restrict spread
- Edge the planting deeply to block runner travel
Potted mint fading with smaller, weaker leaves
A pot of mint fills with roots and runners faster than almost any herb, and once it's rootbound the soil dries in hours and the leaves shrink. Slide it out and you'll find a dense circling mat. Divide the clump, toss the woody center, and replant the strong outer pieces in fresh soil.
Fix:
- Divide the clump and replant divisions
- Repot into fresh soil in a larger container
- Discard the woody center and keep vigorous outer growth
Speckled, dusty leaves with faint webbing
Hot, dry air invites spider mites, which drain the leaves and leave a stippled, faded look. Tap a leaf over white paper and you'll see the tiny mites move. Knock them back with a hard jet of water, keep the soil moist and the air around the plant humid, and reach for insecticidal soap only if they hang on.
Fix:
- Spray foliage with a strong jet of water to dislodge mites
- Increase humidity and keep soil evenly moist
- Apply insecticidal soap if infestation persists
Toxicity
Mint is a kitchen herb that people eat freely, and it poses little danger to animals. The essential oils can give a pet a mild stomach upset if it grazes on a large amount, so keep grazing in check. The one real warning is pennyroyal, a poisonous relative, which you should never confuse with garden mint or grow around animals.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
A nibble does no harm, but a cat that grazes on a lot of leaves can drool and bring up vomit. The essential oils are the irritant, so the upset stays mild and passes once the plant is out of reach.
Dogs Mild
Most dogs sniff and move on. One that chews through a patch may get an upset stomach with vomiting or loose stools, which usually settles on its own.
Horses Mild
A horse would have to eat a good mouthful to feel it. When that happens the oils bring on mild colic and loose droppings rather than anything serious.
Rabbits Mild
A leaf or two is fine, but the strong oils can give a rabbit gas and a loose, runny stomach if it eats a pile. Keep mint to the odd small treat.
Livestock Mild
Goats, sheep, and cattle rarely seek mint out because of the sharp smell. A grazing animal that does work through a stand may show some digestive upset, though it stays minor.
Birds Caution
There's little solid data on birds and mint, so play it safe. Offer only a small leaf now and then and skip any concentrated mint oil entirely.
People Safe
Mint is a kitchen herb eaten fresh, dried, and brewed into tea with no trouble at all. The one caveat is its lookalike pennyroyal, which is genuinely poisonous, so don't confuse the two.
Common garden mint (Mentha spicata) causes only mild GI signs, but its dangerous relative pennyroyal (Mentha pulegium) contains high levels of pulegone and is seriously toxic, capable of causing liver damage in pets and people; do not confuse or substitute the two.
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
Dozens of mints exist, but a few do most of the work in the kitchen and garden. These are the ones worth knowing by name.
Spearmint (Mentha spicata)
This is the everyday culinary mint, with bright green pointed leaves and a sweet, mild flavor that suits both cooking and cold drinks.
Peppermint (Mentha × piperita)
A natural cross between spearmint and water mint, peppermint carries far more menthol and tastes sharper and cooler on the tongue.
'Kentucky Colonel' Spearmint
A big-leaved spearmint selection that bartenders reach for first when they're muddling mint juleps.
How to propagate
Mint multiplies almost on its own, and a single plant gives you all the copies you need. Take cuttings or split a clump rather than sowing seed, since seed-grown mint rarely tastes like its parent.
DivisionEasy
Spring or early fall · 2 to 4 weeks
Division is the surest way to keep a named mint true to type. In spring or early fall, lift an established clump and pull or cut it into pieces that each carry roots and runners, then replant them. Watered in, the divisions take hold within 2 to 4 weeks and start putting out fresh growth.
Stem cuttingsEasy
Spring through summer · 1 to 2 weeks to root
Cuttings are almost foolproof from spring through summer. Snip 10 to 15 cm (4 to 6 inch) stem tips and stand them in water or push them into moist soil, and roots appear in 1 to 2 weeks. Skip seed here, since it gives uneven results and you can't count on the flavor coming true.
Myths
Every kind of mint is dangerously poisonous to pets and should never grow near animals.
Garden mint earns only a mild rating from the ASPCA, and the worst a grazing pet gets is a passing stomach upset. The real danger is its relative pennyroyal, whose pulegone can damage the liver. Grow ordinary spearmint without worry, but keep pennyroyal well away from animals.
Mint is a tidy, well-behaved herb you can drop in anywhere in the garden.
Mint travels by runners above and below the soil and will swamp a bed in a single season. Plant it in a buried bottomless pot or a sharply edged bed and it stays put, but turn it loose in open ground and you'll be pulling it out for years.