How to Grow Mint From Seed

Mint is a cool-friendly perennial that is easy to start in spring. Sow seeds indoors 8 to 10 weeks before your last frost, or direct-sow outdoors once the soil has warmed and frost has passed. In mild zones you can also sow in early fall. Because mint spreads by underground runners, most gardeners start it in a pot to keep it in bounds from day one.

Mint seeds are tiny and need light to germinate, so surface-sow them on moist seed-starting mix and press them in gently without covering. Keep the mix at about 65 to 70F, lightly misted and never soggy, and sprouts appear in roughly 10 to 16 days. Grow in full sun to part shade in rich, consistently moist soil, and thin or transplant seedlings to 18 to 24 inches apart, ideally into a container or a sunken bottomless pot to contain the runners. One honest note: true peppermint (Mentha x piperita) is a sterile hybrid that does not come true from seed, so seed-grown "peppermint" sprouts as spearmint or a fragrant garden mint. If you want guaranteed true peppermint, propagate it from a stem cutting rooted in water for 7 to 10 days, or by dividing an established plant.

Mint practically grows itself once it is up. Keep the soil evenly moist, especially in pots, and give it a light feed in spring to fuel leafy growth. Pinch the tips often to keep plants bushy and to delay flowering, which keeps the leaves at their most flavorful. Mint is famously vigorous, so trim back runners that try to wander, and refresh potted plants by dividing them every couple of years when they get crowded. Spearmint and garden mint are hardy roughly across USDA zones 3 to 11, so in most of the country they die back in winter and come up again in spring, spreading a little wider each year; in the cold north they go fully dormant, while in the warm South and coastal California they can stay green nearly year-round and grow fast, which makes a pot even more useful for keeping them in check.

Mint earns its place in the garden as a fragrant pest-confuser and pollinator plant, and its blooms draw in bees and beneficial insects. Because it spreads, keep it potted near these companions rather than loose in the same bed. These four make especially good neighbors, and you can add any of them in one click:

Begin snipping leaves once plants are 6 to 8 inches tall, usually about 60 to 90 days from sowing. Cut stems just above a pair of leaves, taking no more than a third of the plant at a time, and each cut stem branches into two for a bushier plant. Harvest in the morning and just before flowering for the strongest aroma. Mint keeps giving all season and comes back bigger every year.

Mint makes a quick, bright cup of tea: steep a handful of fresh sprigs in hot water for a few minutes. In the kitchen it goes with fruit salads, yogurt sauces, peas, lamb, tabbouleh, and desserts, and it is the mint in mojitos and mint juleps. In the garden its scent helps mask the smell of nearby crops from some pests, and the late-summer flowers pull in bees and butterflies. Pick leaves before the plant flowers, when they taste strongest.

• Spreading out of control: mint's runners take over fast. Grow it in a pot or a sunken bottomless container and trim wandering runners.
• Weak or off flavor from seed: seed-sold "peppermint" is really spearmint or a mix, since true peppermint is a sterile hybrid. For guaranteed peppermint, root a cutting or divide a known plant.
• Slow germination: the seeds need light, so surface-sow and do not bury them, keep the mix at 65 to 70F, and mist to keep it evenly moist.
• Rust or powdery mildew: give plants airflow, avoid wetting the leaves late in the day, and cut back crowded, tired growth to refresh it.
• Leggy, pale growth: usually too little light. Grow in full sun to part shade and pinch the tips to keep it bushy.