How to grow Stevia in New Zealand
Stevia is a small, leafy herb whose leaves are 200 to 300 times sweeter than sugar, with no calories, so a leaf or two sweetens a cup of tea. It is frost tender, so in most of New Zealand it is grown as a summer annual or potted up for winter; only the frost-free north keeps it going year round.
📖 Our full guide: How to Grow Stevia in New Zealand
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| Northland | September to December | |
| Auckland | September to December | |
| Waikato & Bay of Plenty | October to December | Plant from October, once the inland frosts are over in late September. Warm coastal Bay of Plenty gardens can start a few weeks earlier under cover. |
| Central North Island | November and December | |
| Wellington & Lower North Island | October to December | Plant Oct to Dec once the soil has warmed, in a sunny spot sheltered from the wind. |
| Nelson & Marlborough | October to December | Frost tender. Plant Oct to Dec once the frosts finish; treat it as a summer annual or pot it up for winter. |
| Canterbury | November and December | Frost tender. Plant Nov to Dec once the frosts finish in mid October; treat it as a summer annual or pot it up for winter. |
| Otago & Southland | November and December | Frost tender. Plant after the last frost in late October and treat it as a summer annual, or pot it up for winter. |
| Central Otago | November and December | Frost tender. Plant after the last frost in early November and treat it as a summer annual, or pot it up and bring it under cover before autumn frost. |
Where to plant
Stevia likes full sun and light, fertile, free-draining soil that stays moist. It will take dry soil once established, but it does not like wet roots, especially in winter.
- Northland and Auckland: plant from September. It can keep going year round in frost-free gardens, though it may go semi-deciduous in winter.
- Waikato and the Bay of Plenty: plant from October, once the inland frosts are over in late September. Warm coastal Bay of Plenty gardens can start a few weeks earlier under cover.
- Wellington and Nelson: plant from October to December once the soil has warmed, in a sunny spot out of the wind.
- Central North Island, Canterbury, Otago and Southland: plant in November or December after the last frost.
- In frosty districts, treat stevia as a summer annual, or pot it up and bring it under cover before the first autumn frost.
How to plant
- Buy a plant, or sow seed in spring in seed-raising mix in a warm spot. Germination can be patchy, so plants or cuttings are easier.
- Plant out once the frosts are over, about 30 cm apart, in soil enriched with compost.
- Water in well and keep the soil moist while the plants establish.
Watering and feeding
Water moderately and regularly; stevia prefers moist soil but tolerates some dryness once established. Feed with a liquid fertiliser once the plants are growing.
Pruning and care through the year
- Pinch out the growing tips regularly for a bushy plant with more leaves.
- Pick the leaves before the plant flowers, when sweetness is at its peak.
- Protect from frost, or lift and pot up for winter in cold areas.
Harvesting
Pick leaves as needed through summer, and harvest heavily just before flowering. Dry the leaves on a tray in an airy, shady place, then crumble or grind them and store in a jar for winter. Use sparingly: fresh or dried leaves are intensely sweet.
Growing in pots
Stevia grows well in a pot of free-draining potting mix in full sun, starting from about 20 cm wide. A pot is the easiest way to keep it through winter in frosty areas, by moving it under cover.
Propagation
Take tip cuttings through summer and root them in pots of propagation mix. Cuttings are the easiest way to keep a sweet plant going from year to year.
Varieties
- Stevia (Stevia rebaudiana)
Companion planting
Stevia is a small herb that fits into herb beds and between vegetables.
Good companions
Pests and diseases
Stevia has few pests. Wet roots cause the most losses.
Stevia is rarely troubled by pests.
Diseases to watch for
- Root rot Plants wilt and die in wet, poorly drained soil, especially in winter.
- Root rot in wet
Common questions
How sweet is stevia?
The leaves are about 200 to 300 times sweeter than sugar and have no calories. A single fresh leaf sweetens a cup of tea.
Will stevia survive winter?
Only in frost-free gardens, mostly in the north, and it may lose some leaves. Elsewhere, grow it as a summer annual or pot it up and keep it under cover over winter.
When should I harvest stevia?
Pick leaves as needed, and harvest the main crop just before the plant flowers, when the leaves are sweetest.
How do I dry stevia leaves?
Spread them on a tray or hang stems in an airy, shady place until crisp, then crumble or grind them and store them in an airtight jar.
Can I grow stevia from cuttings?
Yes. Tip cuttings taken in summer root readily and are an easy way to keep your plant going.
Sources we checked: Yates NZ: How to grow stevia; Kings Seeds: Stevia.