When to Plant Sweet Corn in Canberra, Cold / Highland Guide
Sow October to December. Right now in October you can sow.
Grow Sweet Corn in your space
Also called corn, maize.
- Planting window
- Sow once frost has passed and soil is warm, in two or three plantings three weeks apart. January sowings often fail to finish before autumn...
- Days to harvest
- about 11 weeks
- Sunlight
- Full sun (minimum 8 hours). No shade tolerance.
- Water needs
- Deep water 2-3 times weekly. CRITICAL: increase at tasselling/silk stage. Water stress...
- Spacing
- 30cm apart, 60cm between rows
- Soil pH
- 5.8-7.0
- Shop price
- $11.76/kg average
Published · Last reviewed · By GardenBuddy.au
Growing advice is reviewed by hand. Planting dates, current conditions and prices on this page update daily.
This Sweet Corn guide is written for the Cold / Highland zone, which takes in Canberra, Cooma and Bright. Somewhere else? Your postcode picks the right one.
Not your zone? Cairns Brisbane Sydney Melbourne Alice Springs Perth
Also handy: will it frost this week? and what grows in shade.
Photo: Wikimedia Commons
Sweet corn is a warm-season grass requiring block planting for wind pollination. Freshly picked corn is dramatically sweeter than shop-bought because sugars convert to starch within hours of picking. Requires significant space (minimum 4x4 block) and cannot be grown as single plants or rows.
See what grows now in your own postcode
Planting Calendar for Cold / Highland
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| - | - | - | - | - | - | - | - | - | S | S/T/D | T/D |
S = Seed Tray T = Transplant D = Direct Sow
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Current Growing Conditions
Soil temperature: 13.6°C (optimal range: 16–35°C) ✗ Outside optimal range
Modelled from Open-Meteo forecast (Canberra), not a live sensor.
What this month normally looks like
In October the Cold / Highland zone normally runs 20°C by day and 7°C overnight, with about 58 mm of rain over 7 or 8 wet days. The coldest October night on record across the zone was -6.4°C, so a late frost is not out of the question. Averages 1991 to 2026, 15 postcodes, SILO.
How to Grow Sweet Corn in Cold / Highland Australia
When to Plant
Sow once frost has passed and soil is warm, in two or three plantings three weeks apart. January sowings often fail to finish before autumn frost.
- Soil
- Deep, fertile, well-drained soil enriched with compost and aged manure. Heavy feeder.
- pH Range
- 5.8-7.0
- Sunlight
- Full sun (minimum 8 hours). No shade tolerance.
- Spacing
- 30cm apart, 60cm between rows
- Watering
- Deep water 2-3 times weekly. CRITICAL: increase at tasselling/silk stage. Water stress causes bare cob patches.
Companion plants: Beans (Three Sisters), Pumpkin/Squash, Cucumber
Avoid planting near: Tomato (shared corn earworm)
Grow before, grow after
Sweet Corn belongs with the other fruiting crops, the fruiting crops turn of a four turn bed rotation.
- Grow before it
- Leafy greens and brassicas (Lettuce, Silverbeet, Broccoli)
- Grow after it
- Roots and alliums (Carrot, Beetroot, Onion)
Give the bed 3 turns before other fruiting crops go back in. Corn, okra and sunflower are heavy feeders that sit with the fruiting crops in the cycle.
Cold / Highland Growing Tips for Sweet Corn
Recommended Varieties
- Golden Bantam (70 days)
- Early Gem (65 days)
Key Challenges
- Very short season
- Cool nights
- Narrow pollination window
Pro Tips
- 65-75 day varieties only
- Start indoors with heat
- Row covers first weeks
Harvesting Sweet Corn
When ready: Silks brown/dry. Cob full and firm through husk. Kernel exudes milky juice when pierced with thumbnail (milk stage).
How to harvest: Grasp cob, snap downward while twisting. Eat immediately. Sugar converts to starch within hours.
Preserving: pressure canning
6 tested pressure-canning recipes for Sweet Corn: 4 where it is the crop being canned and 2 where it is a main ingredient. Each one comes from published home canning guidelines. The conversion to Australian units is ours, with psi beside every kPa. Always follow your pressure canner's manual.
Worth growing?
A 2.4 m × 1.2 m bed fits 12 plants, about $35 worth at today’s Aldi, Coles, IGA and Woolworths prices, checked today.
That is roughly 3 kg at $11.76 a kilo.
Draw your sweet corn bed → No account needed.
Common Sweet Corn Pests in Cold / Highland Zones
Corn Earworm and Fungal Infections, risk: LOW (score: 23/100)Organic prevention (Corn Earworm (Helicoverpa)): Remove old plants. Crop rotation.
Where to next
Supermarket Price
Current average retail: $11.76/kg (12-month range: $6.98–$16.25)
Grow your own and save on grocery bills.
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Open the planting dashboard Join GardenBuddy.auCommon Questions About Sweet Corn
When do you plant sweet corn in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): Mar to Sep
- Subtropical (Brisbane): Jan to Feb, Sep to Dec
- Warm Temperate (Sydney): Jan, Sep to Dec
- Cool Temperate (Melbourne): Oct to Dec
- Cold / Highland (Canberra): Oct to Dec
- Arid / Semi-Arid (Alice Springs): Jan, Aug to Oct, Dec
- Mediterranean (Perth): Jan, Sep to Dec
Does sweet corn grow all year round in Canberra?
No. In the Cold / Highland zone the planting months are Oct to Dec. Outside that window it either bolts, sulks or gets cut down by the weather.
What else is sweet corn called?
Sweet corn is the usual Australian name. Overseas seed packets and recipes call it corn, maize. Same plant, same growing advice.
Which zone am I in?
Type your postcode into the box under the heading and the page 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 Cold / Highland zone, Canberra is its reference city.