The mint family is vast and cross pollination is difficult to control, so many sources suggest that mint will not come true from seed. Our mint seeds are grown in isolation and bred with care in a greenhouse setting.
Zone: Hardy to Zone 5
When I Get My Seedling Home
Keep seedlings under very bright light to prevent legginess. Artificial lights are ideal, but a bright (ideally, south-facing) room will work for the short term. You may have to pot on seedlings more than once before they go out to allow for root growth. This is done by transplanting them into a slightly larger container with enough additional soil to keep the container mostly full. Keep the soil moist by daily watering and allow for free drainage so the plants are never sitting water.
Do not transplant outside until daytime temperatures are steadily 10°C (50°F) or warmer. This may mean keeping seedlings indoors for up to a month. The plants should not require any fertilizer until transplant time.
Mint spreads in the garden with gusto via a vigorous root system, so it may be preferable to confine it to planters on the balcony. Space transplants into the garden with 30-90cm (12-36") between each. They will rapidly fill in a small garden space or raised bed. Prune plants back hard in early summer to promote good top growth. Bring some inside to grow in a small container over winter if you have a brightly lit windowsill.
Clip leaves or branches as needed throughout the year. Mint is so hardy and tough that it will grow right back. Dry the leaves and flowers for peppermint tea, or use them fresh. The flowers are edible and make salads and sweets come to life.
Mint attracts earthworms, hoverflies and predatory wasps, and repels cabbage moths, aphids, and flea beetles. Mint is invasive, so it may be better to use cut mint as a mulch around Brassicas, or to restrain it in containers around the vegetable garden. Avoid planting near parsley.
More on Companion Planting.