When to Plant Watermelon in Brisbane, Subtropical Guide
That soil figure is read off our own weather station in South East Queensland at 21:55 yesterday, not a model.
What this month normally looks like in Subtropical
In October the Subtropical zone normally runs 27°C by day and 15°C overnight, with about 77 mm of rain over 7 wet days. The coldest October night on record across the zone was -0.2°C, so a late frost is not out of the question. Averages 1991 to 2026, 33 postcodes, SILO.
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This Watermelon guide is written for the Subtropical zone, which takes in Brisbane, the Gold Coast and the Sunshine Coast. Somewhere else? Your postcode picks the right one.
Not your zone? Cairns Sydney Melbourne Canberra Alice Springs Perth
Also handy: will it frost this week? and what grows in shade.
- Planting window
- Aug to Dec
- Days to harvest
- about 12 weeks
- Sun
- Full sun
- Water
- Regular
- Spacing
- 150 cm apart
- Soil pH
- 6.0–7.0
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.
Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.
Photo: Wikimedia Commons
Planting Calendar for Subtropical
- Jan -
- Feb -
- Mar -
- Apr -
- May -
- Jun -
- Jul -
- Aug S
- Sep S/T/D
- Oct S/T/D
- Nov S/T/D
- Dec T/D
S = Seed Tray T = Transplant D = Direct Sow
Want a nudge when it is sowing time?
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How to Grow Watermelon in Subtropical Australia
- Soil
- Sandy loam to loam, well-drained, enriched with compost. Sandy soils warm fastest. Watermelons tolerate slightly sandier conditions than most cucurbits.
- 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 (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.
- Good companions
- Radish (trap crop for flea beetles), Nasturtium, Sweet Corn, Sunflower
- Keep away from
- Potato
- 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 cucurbits go back in. Pumpkin, cucumber and zucchini want a bed with fresh compost dug through.
Subtropical Growing Tips for Watermelon
Recommended Varieties
- Crimson Sweet
- Sugar Baby
- Moon and Stars
- Ali Baba
Key Challenges
- Fruit fly
- Space requirements
- Powdery mildew late season
Pro Tips
- Needs the full summer heat period
- Sugar Baby is compact (2-4kg fruit) for smaller gardens
- Reduce watering 2 weeks before harvest
Pests and problems for Watermelon in Subtropical
- Fungal Infections Moderate
- Queensland Fruit Fly Fruit fly Watch
- Mosaic Viruses Watch
- Root-knot Nematode Watch
- Two-spotted spider mite Watch
- Fusarium Wilt Crop rotation (7+ years for watermelon-specific Fusarium). Resistant varieties. Grafted plants. pH 6.5+. Watch
- Downy Mildew Watch
- Powdery Mildew Good spacing. Remove affected leaves. Watch
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.
Storing and preserving watermelon
How to keep it
- Freezing (for smoothies). Cut into cubes, remove seeds. Freeze on tray, bag when solid. Use directly in smoothies or granita. Keeps: 12 months.
- Dehydrating. Slice flesh thin (5mm). Dehydrate at 55C for 12-18 hours until leathery. Sweet chewy candy-like snack. Keeps: 6 months.
- Fresh eating (best option). Best fresh. Whole watermelon stores 2 weeks at room temp, 3 weeks refrigerated. Cut melon lasts 3-5 days refrigerated. Keeps: 2-3 weeks whole, 3-5 days cut.
- Watermelon Rind Pickle. Peel green outer rind. Cube white inner rind. Soak overnight in salt water. Simmer in vinegar/sugar/spice syrup until translucent. Jar hot. Keeps: 12 months.
What watermelon 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 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): Aug to Dec
- Warm Temperate (Sydney): Sep to Dec
- Cool Temperate (Melbourne): Oct to Dec
- Cold / Highland (Canberra): Oct to Dec
- Arid / Semi-Arid (Alice Springs): Jan, Aug to Dec
- Mediterranean (Perth): Aug to Dec
Can you grow watermelon all year round in Brisbane?
No. In the Subtropical zone the planting months are Aug to Dec. Outside that window it either bolts, sulks or gets cut down by the weather.
When should I plant Watermelon in Brisbane?
Plant from September to December for the long warm season melons need. Later plantings ripen in the wet and get mildew.
What soil temperature do Watermelon need?
Watermelon germinate best when soil temperature is between 21°C and 35°C.
How do I know when Watermelon are ready to harvest?
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.
What are the best Watermelon varieties for Brisbane?
Recommended varieties for the Subtropical zone include: Crimson Sweet, Sugar Baby, Moon and Stars, Ali Baba.
What grows well with Watermelon?
Good companion plants for Watermelon include: Radish, Nasturtium, Sweet Corn, Sunflower.
Are watermelon salt tolerant?
Only a little. Watermelon 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 Subtropical zone, Brisbane is its reference city.