When to Plant Sweet Corn in Canberra — Cold / Highland Guide
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.
Current Growing Conditions
Soil temperature: 18.9°C (optimal range: 16–35°C) ✓ Ready to plant
How to Grow Sweet Corn in Cold / Highland Australia
When to Plant
November to December. Short season.
- 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)
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.
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