What to Plant in December — Subtropical Australia
Your complete December planting guide for subtropical climate zones. Whether you're in Brisbane, Gold Coast, or Sunshine Coast, this guide tells you exactly what to sow from seed, plant as seedlings, and harvest this summer.
Covers: Brisbane, Gold Coast, Sunshine Coast, Lismore, Coffs Harbour and surrounding subtropical postcodes(4000 (Brisbane), 4217 (Gold Coast), 4557 (Sunshine Coast))
Subtropical Climate — December Overview
Warm summers and mild winters. Frost-free coastal areas allow near year-round growing.
December falls in summer for most of Australia, but in subtropical zones this means typical seasonal shifts that guide what crops perform best. The recommendations below are calibrated specifically for subtropical conditions with local rainfall patterns, temperature ranges, and frost dates in mind.
Sow from Seed
Direct or in punnets
- Beans
- Cucumber
- Sweetcorn
- Basil
- Okra
- Pumpkin
- Zucchini
- Chilli
- Capsicum
- Rockmelon
These crops perform best when direct-seeded or started in seed trays in December for subtropical conditions.
Plant as Seedlings
Transplant-ready
- Eggplant
- Capsicum
- Basil
- Sweet Potato slips
- 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
- Tomato
- Cucumber
- Beans
- Zucchini
- Capsicum
- Eggplant
- Sweetcorn
- Basil
Crops typically ready for harvest in December in subtropical zones, from plantings made in previous weeks.
December Tip for Subtropical Gardens
Peak summer harvest season — keep beds well watered, mulched, and harvested regularly. Humidity encourages fungal disease; water at the base only and ensure good airflow between plants. A mid-December sowing of beans will produce in late February.
December Garden Tasks — Subtropical Checklist
Soil Preparation
Subtropical 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 subtropical zones benefit from worm castings mixed into the top layer.
Watering Guide
In subtropical zones during summer, water deeply and less frequently to encourage deep root systems. Morning watering reduces fungal disease risk. Raised beds typically need watering every 2–3 days in summer heat.
Pest & Disease Watch
Subtropical 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 subtropical 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 Brisbane planting in December faces entirely different challenges and opportunities than someone in a cool alpine area like Canberra or Hobart.
For subtropical 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 subtropical 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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