About Garden Planner

About WhatoGrow Garden Planner

Free, postcode-precise planting advice for Australian gardeners — built on real BOM climate data.

What is WhatoGrow Garden Planner?

WhatoGrow Garden Planner is a free Australian gardening tool that tells you exactly what to sow, plant, and harvest each month — based on your postcode, not a vague region. It covers all 6 Australian climate zones and all states and territories.

There's no account and no subscription. You enter your postcode, we match it to Bureau of Meteorology climate data, and you get a calendar that reflects your actual garden conditions: soil temperatures, frost risk, and daylight hours — month by month. The app is supported by a small number of contextual ads.

Our advice is precise because Australia is vast and its climates don't fit neatly into a handful of zones. A suburb in the Blue Mountains and one on the Sydney coast are both called “temperate” — but their last frost dates differ by weeks. Garlic that should be planted in June in Melbourne won't form bulbs correctly in Brisbane. Broccoli started in February in Hobart needs to start in April in Sydney. Your postcode gets you the right window.

Start with your postcode on the home page.

How it works

  1. Enter your postcode. We look it up against the Australian Bureau of Statistics postcode file to find your suburb, state, and geographic coordinates.
  2. We load your climate data. Monthly average minimum and maximum temperatures, frost day counts, and your climate zone are retrieved from our processed BOM dataset — covering over 800 Australian postcodes directly, with interpolation for the rest.
  3. Your calendar is calculated.Each plant's sowing, transplant, and harvest windows are evaluated against your local climate month by month. Frost-sensitive plants are flagged as “avoid” during frost-risk months. Heat-stressed crops are similarly marked. The result is a calendar specific to your location.

Climate zones covered

WhatoGrow Garden Planner covers all six major Australian climate zones:

ZoneCharacteristicsExample cities
TropicalWet/dry seasons, high humidity, no frostDarwin, Cairns, Broome
SubtropicalHot humid summers, mild winters, rare frostBrisbane, Gold Coast, Townsville
TemperateFour seasons, moderate rainfall, occasional frostSydney, Melbourne, Perth, Adelaide
Semi-aridLow rainfall, high temperature range, inlandAlice Springs, Broken Hill, Longreach
Cool temperateCold winters with regular frost, cool summersHobart, Ballarat, Canberra
AlpineShort growing season, heavy frost, possible snowMount Hotham, Thredbo, Falls Creek

Pet safety information

Each plant carries pet safety ratings for dogs, cats, birds, and small mammals (guinea pigs, rabbits, rats). The ratings use a three-tier system:

  • Safe — generally not considered toxic to that animal class.
  • Mild concern — may cause mild digestive upset in large quantities but not acutely dangerous.
  • Toxic — contains compounds known to cause illness. Keep this plant away from the animal.

Ratings are based on ASPCA Animal Poison Control, Pet Poison Helpline, and Australian Veterinary Association guidance. Common examples: garlic, onion, leek, and chives are toxic to all four animal classes. Tomato leaves and stems are toxic to cats. Parsley is toxic to cats in large quantities. Browse the plants page to see pet safety for every variety.

Animal Poisons Helpline (Australia): 1300 869 738
Available 24/7. Call immediately if your pet has eaten a plant and you are concerned.

Frequently asked questions

Is WhatoGrow Garden Planner free to use?

Yes. No account is required and there's no subscription. The app is supported by a small number of contextual ads — relevant to what you're growing, not to who you are.

How does WhatoGrow Garden Planner know my local climate?

You enter your postcode and we match it to Australian Bureau of Meteorology (BOM) climate data for your area. We use monthly average minimum and maximum temperatures, average frost days, and your climate zone to calculate planting windows.

Why does my postcode matter — isn't one climate zone enough?

No. A suburb in the Blue Mountains and a suburb on the Sydney coast are both "temperate" but their frost risk and temperature ranges differ by weeks. Your postcode gets you the right window, not a rough guess.

Can I grow garlic in Queensland?

Yes, but only in the cooler southern parts of Queensland where winter nights drop below 10°C. Garlic requires vernalisation — a period of cold temperatures — to form bulbs properly. Garden Planner uses your local minimum temperatures to determine if and when a garlic sowing window exists for you.

When should I plant tomatoes in my area?

Tomatoes need soil above 18°C and no frost risk. In tropical Australia, this is April–August (the dry season). In subtropical Queensland, September–October. In temperate zones, October–December after the last frost. In cool temperate and alpine areas, November–January when soils finally warm. Garden Planner calculates this from your postcode's climate data.

Are the plant dates based on moon phases or almanac dates?

No. All planting windows are calculated from temperature and frost data. We focus on soil temperature, air temperature, and frost probability — the factors that actually determine germination and growth.

What does the pet safety rating mean?

"Safe" means the plant is generally not considered toxic to that animal class. "Mild" means the plant may cause mild digestive upset in large quantities but isn't acutely dangerous. "Toxic" means the plant contains compounds known to cause illness. Ratings are based on ASPCA, Pet Poison Helpline, and Australian Veterinary Association guidance. If your pet has eaten something concerning, call the Animal Poisons Helpline on 1300 869 738.

About the data

Climate data is sourced from the Bureau of Meteorology's historical station records and the SILO climate database (for remote and interpolated locations). Postcode boundaries and suburb names use ABS Australian Statistical Geography Standard data.

Plant growing parameters — soil temperature ranges, frost sensitivity, heat stress thresholds, and harvest windows — are researched from Australian horticultural extension publications, seed house guides, and CSIRO growing guides, then validated against grower experience across multiple climate zones.

Data is reviewed and updated seasonally. If you notice an error in a planting window for your area, please get in touch.

Contact & feedback

Found an error? Have a plant you'd like to see added? Notice that your local climate window seems off? We'd love to hear from you.

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