When to Plant Lettuce in Cairns, Tropical Guide
Soil temperature is modelled from Open-Meteo forecast (Cairns), not a live sensor.
What this month normally looks like in Tropical
In October the Tropical zone normally runs 34°C by day and 23°C overnight, with about 53 mm of rain over 5 or 6 wet days. Averages 1991 to 2026, 37 postcodes, SILO.
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This Lettuce guide is written for the Tropical zone, which takes in Cairns, Townsville and Darwin. Somewhere else? Your postcode picks the right one.
Not your zone? Brisbane Sydney Melbourne Canberra Alice Springs Perth
Also handy: will it frost this week? and what grows in shade.
- Planting window
- Mar to Aug
- Days to harvest
- 30 days
- Sun
- Full sun to part shade
- Water
- Regular
- Spacing
- 25 cm apart
- Soil pH
- 6.0–7.0
Lettuce is the most commonly grown salad green in Australian home gardens. Available in four main types: crisphead (iceberg), cos/romaine, butterhead, and loose-leaf.
Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.
Photo: Wikimedia Commons
Planting Calendar for Tropical
- Jan -
- Feb -
- Mar S/D
- Apr S/T/D
- May S/T/D
- Jun S/T/D
- Jul S/T/D (likely to bolt)
- Aug T/D (likely to bolt)
- Sep -
- Oct -
- Nov -
- Dec -
S = Seed Tray T = Transplant D = Direct Sow
Amber = likely to bolt if sown this month, it matures into heat or long days.
Want a nudge when it is sowing time?
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How to Grow Lettuce in Tropical Australia
- Soil
- Light, well-drained soil enriched with compost. Lettuce has shallow roots and prefers loose, friable soil.
- Salt
- Moderately sensitive. Copes with a little salt, but the harvest drops on salty bore water.
- pH Range
- 6.0-7.0
- Sunlight
- Full sun in cool seasons. Part shade essential in warm zones and during warm months to delay bolting.
- Spacing
- 25cm apart, 30cm between rows
- Watering
- Light, frequent watering to keep soil consistently moist. Shallow roots dry out quickly. Morning watering preferred. Drip irrigation or soaker hose ideal. Avoid overhead watering to prevent disease.
- Good companions
- Amaranth (amaranth provides shade), Dwarf Beans, Onion, Cucumber, Carrot
- Keep away from
- Celery (some allelopathic evidence), Parsley (competes for same nutrients)
- Grow before it
- Legumes (Beans - Dwarf, Peas, Broad Beans)
- Grow after it
- Fruiting crops (Tomato, Capsicum, Zucchini)
Give the bed 3 turns before leafy greens go back in. Leaf crops want the nitrogen the legumes left behind.
Tropical Growing Tips for Lettuce
Recommended Varieties
- Darwin (oakleaf, extremely heat tolerant)
- Green Oakleaf
- Red Oakleaf
- Salad Bowl
Key Challenges
- Bolts within days once temperatures exceed 28C
- Humidity promotes fungal diseases
- Slug pressure in wet season
Pro Tips
- Lettuce is fundamentally a marginal crop in the tropics, manage expectations
- Grow only loose-leaf oakleaf types; heading varieties will fail
- Harvest as baby leaf (4-5 weeks) before bolting
Pests and problems for Lettuce in Tropical
- Tomato Spotted Wilt Virus Watch
- Helicoverpa / Corn Earworm / Tomato Grub Watch
- Botrytis (Grey Mould) Watch
- Mosaic Viruses Watch
- Root-knot Nematode Watch
- Thrips Watch
- Downy Mildew Avoid overhead watering. Water in morning. Space for airflow. Grow resistant varieties. Remove crop debris. Watch
- Lettuce Mosaic Virus Use certified virus-free seed. Control aphids. Remove infected plants immediately. Grow resistant varieties. Watch
- Humidity promotes fungal diseases Humidity promotes fungal diseases Watch
- Slug pressure Slug pressure in wet season Watch
Harvesting Lettuce
When ready: Loose-leaf: when leaves are 10-15cm (baby) or 20cm+ (full size). Heading types: when head is firm and full-sized. Cos: when upright head is dense. Harvest before any signs of flower stalk elongation (bolting).
How to harvest: Cut-and-come-again: cut outer leaves at base for loose-leaf types. Whole head: cut at soil level with sharp knife in cool of morning. For cos, can harvest outer leaves or whole head.
Storing and preserving lettuce
How to keep it
- Dehydrating (for powder). Wash and dry leaves. Spread on dehydrator trays. Dry at 52C for 6-10 hours until crispy. Blitz to powder. Use as a mild green powder in smoothies. Note: texture is completely different from fresh. Keeps: 3-6 months.
- Fresh Storage. Wash, dry thoroughly in salad spinner. Wrap in paper towel, place in sealed container in fridge crisper. Or store whole unwashed heads in open plastic bag with paper towel. Keeps: 5-10 days refrigerated (varies by type; crisphead longest, loose-leaf shortest).
What lettuce costs in the shops right now, retailer by retailer, updated daily.
What members get
- Soil and weather from your nearest station
- An email when it's time to sow
- Your own garden plan, including planning from a photo
- Price history and price alerts
- Pest risk alerts for your area
- Full salt and canning detail
Common Questions About Lettuce
When do you plant lettuce in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): Mar to Aug Likely to bolt if sown in July and August.
- Subtropical (Brisbane): Jan to Sep Likely to bolt if sown in August and September.
- Warm Temperate (Sydney): Jan to Nov Likely to bolt if sown in October and November.
- Cool Temperate (Melbourne): all year Likely to bolt if sown in September, October, November and December.
- Cold / Highland (Canberra): Jan to Apr, Aug to Dec Likely to bolt if sown in October, November and December.
- Arid / Semi-Arid (Alice Springs): Feb to Sep Likely to bolt if sown in July, August and September.
- Mediterranean (Perth): Jan to Nov Likely to bolt if sown in October and November.
Can you grow lettuce all year round in Cairns?
No. In the Tropical zone the planting months are Mar to Aug. Outside that window it either bolts, sulks or gets cut down by the weather. Likely to bolt if sown in July and August.
When should I plant Lettuce in Cairns?
Grow through the dry season, focusing on loose-leaf and heat-tolerant types picked young. August sowings are the last before the build-up makes it bolt.
What soil temperature do Lettuce need?
Lettuce germinate best when soil temperature is between 5°C and 25°C.
How do I know when Lettuce are ready to harvest?
Loose-leaf: when leaves are 10-15cm (baby) or 20cm+ (full size). Heading types: when head is firm and full-sized. Cos: when upright head is dense. Harvest before any signs of flower stalk elongation (bolting).
What are the best Lettuce varieties for Cairns?
Recommended varieties for the Tropical zone include: Darwin (oakleaf, extremely heat tolerant), Green Oakleaf, Red Oakleaf, Salad Bowl.
What grows well with Lettuce?
Good companion plants for Lettuce include: Amaranth, Dwarf Beans, Onion, Cucumber, Carrot.
Are lettuce salt tolerant?
Only a little. Lettuce are moderately sensitive to salt, so the harvest drops on salty bore water. Mix salty water with rainwater, and mulch the bed.
Which zone am I in?
Type your postcode into the box near the top of the page and it tells you, and links this crop in your own zone if it differs. Or look it up on the grow zone map. This page is the Tropical zone, Cairns is its reference city.