How to grow Lettuce in New Zealand
Lettuce is one of the quickest, easiest crops, with young leaves ready to pick in about six weeks. Loose-leaf types can be picked a few leaves at a time for weeks, while hearting types such as iceberg are cut whole. In the North Island it can be grown almost year round by choosing the right type for the season; in the south it is a spring to autumn crop.
📖 Our full guide: When to Plant Lettuce in NZ: How to Grow Lettuce by Region
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 | September to May | Skip August in the central North Island. Hard frosts and cold soil stall seedlings, so start in September, under a cloche if you can. |
| Wellington & Lower North Island | August to May | |
| Nelson & Marlborough | August to May | |
| Canterbury | September to March | Start spring sowings in Sep under a cloche or frost cloth, as frosts run to mid October. Make the last sowing in Mar so the crop is ready before winter growth stops. |
| Otago & Southland | October to March | Start spring sowings in Oct under a cloche or frost cloth, as frosts run to late October. Make the last sowing in Mar so the crop is ready before winter growth stops. |
| Central Otago | October to February | Start spring sowings in Oct under a cloche or frost cloth, as frosts run into early November. Make the last sowing in Feb so the crop is ready before winter growth stops. |
Where to plant
Lettuce likes full sun from autumn to spring and some shade through the heat of summer, when hot, dry conditions make it bitter and send it to seed. Grow it in rich, moist, well-drained soil dug through with compost.
It is small and shallow rooted, so it fits between slower crops and grows well in pots, troughs and window boxes.
- Northland, Auckland, Waikato and Bay of Plenty, Wellington, and Nelson and Marlborough: sow from August to May, and in mild northern gardens almost year round. Through January and February choose heat-tolerant loose-leaf types such as Green Mignonette and give afternoon shade.
- Central North Island: sow from September to May. Skip August, when hard frosts and cold soil stall seedlings, and use a cloche for early sowings.
- Canterbury: sow from September to March. Start spring sowings under a cloche or frost cloth, as frosts run to mid October, and make the last sowing in March.
- Otago and Southland: sow from October to March, under a cloche early in the season, as frosts run to late October.
- Central Otago: sow from October to February, with cloches early, as frosts run into early November.
Choosing a variety
| Type | Notes |
|---|---|
| Loose-leaf, for example Green Mignonette and oak leaf types | No firm heart; pick leaves for weeks. Green Mignonette is a classic New Zealand home-garden lettuce, compact and slow to bolt |
| Butterhead and mini cos, for example Buttercrunch, Little Gem and Tom Thumb | Soft or crisp small heads; Little Gem and Tom Thumb suit winter as well as summer |
| Cos, for example Paris Island | Upright and crunchy; pick outer leaves or cut whole. Cos can be grown all year |
| Crisphead or iceberg | Firm, crunchy hearts; best sown in spring. Stop sowing hearting types in midsummer, as they dislike heat |
| Winter types, for example Imperial Triumph | A cold-tolerant hearting lettuce for winter, alongside loose-leaf and winter salad greens |
How to plant
- Sow seed very shallowly, 3 to 5 mm deep, direct in the bed or in trays of seed-raising mix. Lettuce seed is tiny, and sown too deep it will not come up.
- Keep the surface moist until seedlings appear. In hot weather, sow in a shaded spot or in trays in a cool place, as seed often fails to germinate in hot soil.
- Transplant seedlings when they have two sets of true leaves, about 3 to 4 cm high, or thin direct sowings to 20 to 30 cm apart.
- Water in and mulch with pea or lucerne straw.
- Sow a short row every two to three weeks for a steady supply.
Watering and feeding
Water regularly so the soil stays evenly moist. Lettuce that dries out turns bitter and bolts. Water the soil in the morning rather than wetting the leaves late in the day, which encourages mildew.
Feed weekly with a liquid vegetable fertiliser for fast, tender growth.
Harvesting
Pick loose-leaf types a few outer leaves at a time from about six weeks, leaving the centre to keep growing; started early, one plant gives leaves for weeks. Cut hearting types whole once the head feels firm, before they start to bolt.
Pick in the cool of the morning and refrigerate straight away. Once lettuce runs up a flower stalk the leaves turn bitter; pull it out, or let it flower and set seed for a self-sown patch.
Growing in pots
Lettuce is ideal for pots at least 20 cm wide. Use quality potting mix in full sun in the cool months and part shade in summer, keep it moist, and feed weekly. Loose-leaf types give the longest picking from a small space.
Companion planting
Lettuce is quick and shallow rooted, so it fills gaps between slower crops and pairs well with many vegetables.
Good companions
- Carrot Carrots grow slowly below while lettuce crops quickly above, sharing the space well.
- Radish Another quick crop for the same rows, pulled before the lettuce fills out.
- Onion Slim onions and chives take little space beside lettuce.
- Strawberry Lettuce makes a quick crop at the edge of a strawberry bed.
- Marigold Its flowers bring in hoverflies and other beneficial insects that eat aphids.
- Chives
Keep apart
Avoid planting these close to lettuce.
- Parsley Traditional companion lists keep them apart.
Pests and diseases
Slugs and snails are the main lettuce pests in New Zealand gardens, especially on young plants. Aphids and mildew follow in warm or damp spells.
Pests to watch for
- Slugs Ragged holes and slime trails, often seedlings eaten overnight.
- Snails Ragged holes and slime trails, worst in damp weather.
- Aphids Small green or grey insects in the heart and under leaves.
Diseases to watch for
- Downy mildew Yellow, angular patches on the upper leaf with white fuzz underneath, in cool, damp weather.
- Sclerotinia Plants collapse with a wet rot at the base and white, cottony mould with black bodies. Remove and bin affected plants.
Common questions
Why does my lettuce taste bitter?
Heat, dry soil and age make lettuce bitter, and bolting makes it worse. Keep it evenly watered, give it afternoon shade in summer, and pick it young.
Why won't my lettuce seed germinate in summer?
Lettuce seed often fails in hot soil. Sow in trays somewhere cool and shaded, or sow in the evening and keep the seedbed moist and shaded until seedlings appear.
Which lettuce can I grow in summer?
Loose-leaf types such as Green Mignonette and oak leaf, and cos, cope best with heat. Stop sowing hearting types such as iceberg in midsummer, and give all lettuce afternoon shade.
Which lettuce can I grow in winter?
Tom Thumb, Little Gem, cos, loose-leaf oak leaf types and the cold-tolerant hearting variety Imperial Triumph, along with winter salad greens such as corn salad.
How do I pick lettuce so it keeps growing?
With loose-leaf and cos types, take a few outer leaves at a time and leave the centre. Hearting types are best cut whole.
How do I stop slugs eating my lettuce?
Protect seedlings with slug bait or traps, go out with a torch on damp evenings to remove them, and keep the area around the bed tidy.
Sources we checked: Tui: Lettuce growing guide; Yates NZ: How to grow lettuce.