When to Plant Broccoli in Canberra — Cold / Highland Guide
Photo: Wikimedia Commons
Broccoli is a cool-season brassica that produces a large central head followed by smaller side-shoots over several weeks. It is one of the most nutritious vegetables available and grows well across most Australian zones during the cooler months. The key to success is timing (avoiding heat-induced bolting) and managing the ever-present Cabbage White Butterfly.
Planting Calendar
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S/T | S/T | T | — | — | — | — | S | S/T | S/T | S/T | S/T |
S = Seed Tray T = Transplant D = Direct Sow
Current Growing Conditions
Soil temperature: 18.9°C (optimal range: 10–30°C) ✓ Ready to plant
How to Grow Broccoli in Cold / Highland Australia
When to Plant
Sow in trays under cover September-February. Transplant out after last frost. Short growing season limits to one main crop.
- Soil
- Rich, moisture-retentive loam with plenty of compost and well-rotted manure. Firm soil preferred - brassicas dislike loose, fluffy beds.
- pH Range
- 6.0-7.0
- Sunlight
- Full sun (minimum 6 hours). Tolerates partial afternoon shade in warmer zones.
- Spacing
- 45cm apart, 60cm between rows
- Watering
- Consistent deep watering 2-3 times weekly. Brassicas are shallow-rooted and stress quickly in dry conditions. Inconsistent watering causes hollow stems and poor head formation. Drip irrigation or soak
Companion plants: Celery, Onion, Chamomile, Dill, Rosemary, Sage
Avoid planting near: Strawberry, Tomato, Capsicum, Other brassicas (rotation)
Cold / Highland Growing Tips for Broccoli
Recommended Varieties
- Waltham 29
- Marathon
- Purple Sprouting
- Belstar
Key Challenges
- Short frost-free window
- Hard frosts kill immature plants
- Slow growth at altitude
Pro Tips
- Start seeds indoors/under cover to maximise growing season
- Cloches and frost cloth extend the season both ends
- Purple Sprouting types that overwinter are excellent here
Harvesting Broccoli
When ready: Central head should be 10-15cm diameter with tight, dark green buds. Harvest BEFORE any yellow flowers appear. Individual buds should be compact and firm, not swollen or loose.
How to harvest: Cut main head with 10-15cm of stem attached using a sharp knife, cutting at an angle to shed water from the cut surface. LEAVE THE PLANT IN THE GROUND - side shoots will develop from leaf axils and produce smaller broccoli heads for 4-8 weeks after main head harvest.
Common Broccoli Pests in Cold / Highland Zones
Organic prevention: Install netting BEFORE you see the first butterfly. Once eggs are laid under netting, you've trapped the problem inside. Inspect leaf undersides weekly for yellow egg clusters and remove immediately.
Supermarket Price
Current average retail: $5.77/kg (range: $4.56–$13.00)
Grow your own and save on grocery bills.
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