When to Plant Watermelon in Canberra, Cold / Highland Guide
Sow September to November. Right now in September you can sow.
Published · Last reviewed · By Garden Buddy
Growing advice is reviewed by hand. Planting dates, current conditions and prices on this page update daily.
This Watermelon 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
Watermelon is a warm-season vine crop native to Africa, requiring long hot summers and ample space. Australia's arid interior and northern regions produce some of the sweetest watermelons in the world. Home-grown watermelon in warm zones is deeply rewarding. Requires substantial space (each vine can spread 3-4m), consistent warmth, and patience (80-100+ days to maturity).
Planting Calendar for Cold / Highland
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| - | - | - | - | - | - | - | - | S | S | T | - |
S = Seed Tray T = Transplant D = Direct Sow
Want a nudge when it is Watermelon sowing time in Canberra?
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Current Growing Conditions
Soil temperature: 11.2°C (optimal range: 21–35°C) ✗ Outside optimal range
Modelled from Open-Meteo forecast (Canberra), not a live sensor.
How to Grow Watermelon in Cold / Highland Australia
When to Plant
Greenhouse required. Not viable outdoors.
- Soil
- Sandy loam to loam, well-drained, enriched with compost. Sandy soils warm fastest. Watermelons tolerate slightly sandier conditions than most cucurbits.
- pH Range
- 6.0-7.0
- Sunlight
- Full sun (minimum 8 hours). More heat and sun = sweeter fruit.
- Spacing
- 150cm apart, 250cm between rows
- Watering
- Deep regular watering during vine growth and fruit development. CRITICAL: reduce watering 2 weeks before harvest to concentrate sugars. Excess water at maturity dilutes sweetness and causes splitting.
Companion plants: Corn, Sunflower, Nasturtium, Radish (trap crop for flea beetles)
Avoid planting near: Potato, Other Citrullus if seed saving
Cold / Highland Growing Tips for Watermelon
Recommended Varieties
- Sugar Baby, greenhouse only
Key Challenges
- Insufficient heat
- Very short season
Pro Tips
- Greenhouse only
- Sugar Baby fastest to mature
- Honestly not the best use of cold-highland greenhouse space
Harvesting Watermelon
When ready: Multiple indicators needed: 1) Tendril nearest fruit turns brown and dry, 2) Ground spot (where fruit sits) turns from white to creamy yellow, 3) Skin resists thumbnail scratch (hard rind), 4) Dull thud when tapped (not hollow ring). Use ALL indicators together. No single one is reliable alone.
How to harvest: Cut stem cleanly with sharp knife. Do not pull or twist. Handle carefully.
Worth growing?
A 2.4 m × 1.2 m bed fits 1 plant, about $14 worth at today’s Aldi prices, checked today.
That is roughly 4 kg at $3.49 a kilo.
Draw your watermelon bed → No account needed.
Common Watermelon Pests in Cold / Highland Zones
Organic prevention: Net before ripening. Hygiene. Thick-rind varieties less susceptible.
Where to next
Supermarket Price
Current average retail: $3.49/kg (12-month range: $3.49–$3.99)
Grow your own and save on grocery bills.
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Open the planting dashboard Join Garden BuddyCommon Questions About Watermelon
When do you plant watermelon in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): Mar to Jul
- Subtropical (Brisbane): Jan, Jul to Dec
- Warm Temperate (Sydney): Aug to Dec
- Cool Temperate (Melbourne): Aug to Dec
- Cold / Highland (Canberra): Sep to Nov
- Arid / Semi-Arid (Alice Springs): Jan to Apr, Sep to Dec
- Mediterranean (Perth): Aug to Dec
Does watermelon grow all year round in Canberra?
No. In the Cold / Highland zone the planting months are Sep to Nov. Outside that window it either bolts, sulks or gets cut down by the weather.
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.