How to grow Mint in New Zealand
Mint is the easiest herb of all: it grows in sun or shade, in the ground or in a pot, as long as the soil stays moist. The catch is that it spreads by underground runners and will take over a bed, so most gardeners keep it in a pot or a sunken container. Spearmint is the classic kitchen mint, with peppermint, apple mint and many others to try.
📖 Our full guide: How to Grow Mint in New Zealand
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| Northland | August to May | |
| Auckland | August to May | |
| Waikato & Bay of Plenty | August to May | |
| Central North Island | August to May | |
| Wellington & Lower North Island | August to May | |
| Nelson & Marlborough | August to May | |
| Canterbury | August to May | |
| Otago & Southland | August to April | Plant Aug to Apr. Before that the ground is too cold, and later plantings do not root in before the hard frosts. |
| Central Otago | September to March | Plant Sep to Mar so roots establish before the hard frosts. |
Where to plant
Mint is one of the few herbs that grows well in both sun and shade, and it thrives anywhere the soil stays moist. In hot, dry spots it does better with some afternoon shade.
It spreads by underground stems and quickly takes over open ground. Grow it in a pot, a trough, or a bottomless bucket or tub sunk into the bed with the rim above the soil, and keep it away from lawns and other herbs.
- Northland to Canterbury, including Wellington and Nelson and Marlborough: plant from August to May. In Auckland and the north it grows almost all year, slowing in winter.
- Otago and Southland: plant from August to April. Earlier the ground is too cold, and later plantings do not root in before the hard frosts.
- Central Otago: plant from September to March so roots establish before the hard frosts. It dies back in winter and regrows in spring.
Choosing a variety
| Type | Notes |
|---|---|
| Spearmint | The classic garden mint for cooking, mint sauce and drinks; vigorous and easy |
| Peppermint | Stronger, cooler flavour, best for tea |
| Apple mint | Soft, furry leaves with a mild, fruity flavour |
| Chocolate mint | A peppermint type with a hint of chocolate scent |
| Corsican mint | A tiny, creeping mint for between pavers and pots |
Mint does not come true from seed, so for a particular flavour, buy a plant or take a cutting. Pennyroyal is also sold as a mint, but it is toxic and should not be eaten or used for tea.
How to plant
- The quickest start is a cutting: take a 10 cm shoot, strip the lower leaves and stand it in water. It roots within a couple of weeks, ready to plant.
- Or plant a bought plant, or a piece of root with a shoot, into a pot of herb or potting mix, or into a container sunk in the bed.
- Seed can be sown in spring in trays, lightly covered and kept moist.
- Water in well and keep the soil moist.
Watering and feeding
Water regularly so the soil never dries out; mint in pots may need water every day in summer.
Feed regularly with a nitrogen-rich liquid fertiliser to keep fresh, green leaves coming, especially in pots.
Pruning and care through the year
- Prune regularly to keep plants bushy and in check, and cut off flower stems to keep leaves coming.
- Cut the whole plant back hard in late summer or autumn for a flush of fresh growth.
- Repot or divide potted mint every year or two, as it quickly fills a pot and weakens; replant a few healthy runners in fresh mix.
- Pull out any runners that escape over the edge of the container.
Harvesting
Pick sprigs as needed once the plant is growing strongly, taking the tips to encourage bushy growth. The leaves are most aromatic just before flowering.
Fresh mint keeps up to a week in the fridge with the stems in water. Freeze chopped leaves in ice cube trays, or dry bunches in a shady, airy place for tea.
Growing in pots
A pot is the best place for mint. Use a pot at least 20 to 30 cm wide with herb or potting mix, in sun or part shade. Keep it well watered and fed, and divide it once it fills the pot.
Propagation and saving seed
Mint roots very easily. Stand shoot cuttings in water until roots form, or dig up a piece of runner with roots and replant it. Division of a potted plant every year or two keeps it vigorous.
Companion planting
Mint's flowers attract beneficial insects, but keep the plant contained so it does not invade neighbouring crops.
Good companions
- Cabbage A traditional companion; a pot of mint nearby is said to help deter cabbage pests.
- Tomato A traditional companion; its flowers bring in beneficial insects.
Keep apart
Avoid planting these close to mint.
- Parsley The Herb Federation of New Zealand notes that parsley and mint do not grow well together.
Pests and diseases
Mint is tough, but rust can be a problem in crowded, humid conditions.
Pests to watch for
- Aphids Clusters on soft shoot tips.
Diseases to watch for
- Rust Orange pustules on the undersides of leaves and on stems. Cut affected plants right back and bin the cuttings.
- Verticillium wilt Plants wilt and leaves yellow from the bottom up despite moist soil. Replace with healthy cuttings in fresh soil.
Common questions
How do I stop mint spreading?
Grow it in a pot, or plant it in a bottomless bucket or tub sunk into the bed with the rim a few centimetres above the soil, and pull out any runners that escape.
Can mint grow in shade?
Yes. Mint is one of the few herbs that grows well in shade as well as sun, provided the soil stays moist.
Why is my mint going woody and sparse?
Potted mint quickly fills its pot and runs out of food. Divide it every year or two, replant healthy runners in fresh mix, and cut it back hard to bring on new growth.
What are the orange spots on my mint?
That is mint rust. Cut the plant right down and bin the cuttings, then let it regrow; if it keeps coming back, start again with a healthy cutting in fresh mix.
How do I grow mint from a cutting?
Take a 10 cm shoot, strip the lower leaves and stand it in water. Roots appear within a couple of weeks; then pot it up.
Is pennyroyal safe to use like mint?
No. Pennyroyal is toxic and should not be eaten or used for tea, although it is sold among the mints.
Sources we checked: Tui: Mint growing guide; Yates NZ: How to grow mint; Herb Federation of New Zealand: Parsley (parsley and mint).