What to Plant in December — Tropical Australia
Your complete December planting guide for tropical climate zones. Whether you're in Cairns, Darwin, or Townsville, this guide tells you exactly what to sow from seed, plant as seedlings, and harvest this summer.
Covers: Cairns, Darwin, Townsville, Broome, Katherine and surrounding tropical postcodes(4870 (Cairns), 0800 (Darwin), 4810 (Townsville))
Tropical Climate — December Overview
Hot and humid year-round with distinct wet and dry seasons. Minimal frost risk.
December falls in summer for most of Australia, but in tropical zones this means distinct wet or dry season conditions that define your planting choices. The recommendations below are calibrated specifically for tropical conditions with local rainfall patterns, temperature ranges, and frost dates in mind.
Sow from Seed
Direct or in punnets
- Beans
- Sweetcorn
- Okra
- Pumpkin
- Cucumber
- Zucchini
- Watermelon
- Capsicum
- Eggplant
- Chilli
These crops perform best when direct-seeded or started in seed trays in December for tropical conditions.
Plant as Seedlings
Transplant-ready
- Sweet Potato slips
- Basil
- Lemongrass
- Chilli
These crops establish faster from nursery seedlings in December. Harden off for 3–5 days before planting out.
Ready to Harvest
From earlier plantings
- Mango
- Papaya
- Banana
- Beans
- Sweetcorn
- Zucchini
- Cucumber
Crops typically ready for harvest in December in tropical zones, from plantings made in previous weeks.
December Tip for Tropical Gardens
Full wet season — tropical storms and high rainfall. Raised beds are essential for drainage. Focus on pest and disease management. Harvests of heat-loving crops continue; fruiting crops established before the wet will produce abundantly through December.
December Garden Tasks — Tropical Checklist
Soil Preparation
Tropical summers are demanding on soil. Top-dress beds with 5cm of compost before planting and mulch heavily (8–10cm) to conserve moisture and regulate soil temperature. Water-wise gardens in tropical zones benefit from worm castings mixed into the top layer.
Watering Guide
In December, tropical zones have natural rainfall assisting, but ensure drainage is excellent to prevent waterlogging.
Pest & Disease Watch
Tropical summers bring peak pest pressure. Watch for: aphids on new growth (blast with water), white cabbage moth caterpillars, spider mites in dry heat, and powdery mildew on zucchini and cucumber. Inspect plants every 2–3 days and act early.
Succession Planting
Avoid the feast-or-famine cycle by sowing fast-maturing crops — lettuce, radish, Asian greens, and spinach — every 2–3 weeks rather than all at once. In tropical zones during December, a fortnightly succession-sowing rhythm ensures continuous harvests rather than a single glut. Split your available bed space into thirds and plant each third 2 weeks apart. This applies to salad crops year-round and to beans and beetroot in the warmer months.
From the makers
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This guide is a great starting point — Plant Planner goes further with exact sowing dates, quantities based on your family size, companion planting suggestions, and weekly email reminders.
Why Climate Zone Matters for December Planting
Australia spans five distinct climate zones, and the same calendar month means completely different growing conditions depending on where you live. A gardener in Cairns planting in December faces entirely different challenges and opportunities than someone in a cool alpine area like Canberra or Hobart.
For tropical zones specifically, December is peak summer — soil temperatures are high, evaporation is rapid, and heat-loving crops thrive while cool-season vegetables struggle. The planting recommendations on this page account for typical tropical frost dates, average temperatures, and seasonal rainfall patterns.
For even more precision, VeggiePatch Pro uses your exact Australian postcode to determine your specific microclimate, local frost dates, and the optimal planting windows for your suburb. Enter your postcode for a personalised 12-month planting calendar tailored to your exact location — not just your broad climate zone.
Get a Personalised Plan for Your Garden
This guide is a great starting point, but VeggiePatch Pro goes further. Enter your postcode, your bed measurements, and your family size — we'll generate a complete 12-month planting calendar with exact sowing dates, quantities based on how many people you feed, companion planting suggestions, and weekly email reminders.
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