When to Plant Broccoli in Cairns, Tropical Guide

Out of season. Next window opens in April Soil 24.7°C, best 10–30°C

Soil temperature is modelled from Open-Meteo forecast (Cairns), not a live sensor.

What this month normally looks like in Tropical

In October the Tropical zone normally runs 34°C by day and 23°C overnight, with about 53 mm of rain over 5 or 6 wet days. Averages 1991 to 2026, 37 postcodes, SILO.

Jump to section
  1. Planting calendar
  2. How to grow
  3. Local tips and varieties
  4. Pests and problems
  5. Harvesting
  6. Storing and preserving
  7. Other zones and related crops
  8. Common questions

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This Broccoli guide is written for the Tropical zone, which takes in Cairns, Townsville and Darwin. Somewhere else? Your postcode picks the right one.

Not your zone? Brisbane Sydney Melbourne Canberra Alice Springs Perth

Also handy: will it frost this week? and what grows in shade.

Planting window
Apr to Jul
Days to harvest
about 11 weeks
Sun
Full sun to part shade
Water
Regular
Spacing
45 cm apart
Soil pH
6.5–7.5
Shop price
$6.90/kg at one shop

Broccoli is a cool-season brassica that produces a large central head followed by smaller side-shoots over several weeks.

Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.

Broccoli

Photo: Wikimedia Commons

Planting Calendar for Tropical

  • Jan -
  • Feb -
  • Mar -
  • Apr S
  • May S/T
  • Jun T
  • Jul T
  • Aug -
  • Sep -
  • Oct -
  • Nov -
  • Dec -

S = Seed Tray   T = Transplant   D = Direct Sow

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How to Grow Broccoli in Tropical Australia

Soil
Rich, moisture-retentive loam with plenty of compost and well-rotted manure. Firm soil preferred. Brassicas dislike loose, fluffy beds.
Salt
Moderately sensitive. Copes with a little salt, but the harvest drops on salty bore water.
pH Range
6.5-7.5
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 soaker hoses ideal.
Good companions
Nasturtium, Dwarf Beans, Onion, Cucumber, Dill
Keep away from
Capsicum, Garden Cress, Lemongrass, Peach, Pear, Rue, Strawberry, Tomato
Grow before it
Legumes (Beans - Dwarf, Peas, Broad Beans)
Grow after it
Fruiting crops (Tomato, Capsicum, Zucchini)

Give the bed 3 turns before brassicas go back in. The cabbage family is hungry for nitrogen and shares club root and other soil diseases.

Members see the exact salt threshold, how much harvest it loses as salt rises, and what to grow instead. See what members get

Tropical Growing Tips for Broccoli

Recommended Varieties

  • Green Magic (heat-tolerant hybrid)
  • Summer Green
  • Belstar
  • Marathon

Key Challenges

  • Heat causes premature bolting
  • Intense caterpillar pressure year-round
  • Humidity drives fungal diseases
  • Short suitable growing window

Pro Tips

  • Choose heat-tolerant hybrids only. Heritage varieties will bolt
  • Exclusion netting is mandatory, not optional
  • Grow fast, transplant strong seedlings for quickest maturity

Pests and problems for Broccoli in Tropical

Members see each pest score and pest risk alerts for your area. See what members get

Browse the full pest library →

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.

Storing and preserving broccoli

How to keep it
  • Freezing (blanched). Cut into uniform florets. Soak in salted water 30 minutes to evict any hidden caterpillars (essential for organic broccoli). Blanch 3 minutes in boiling water. Ice bath immediately. Drain thoroughly, pat dry. Lay on tray to flash-freeze, then transfer to freezer bags. Keeps: 12 months.
  • Dehydrating. Blanch florets 3 minutes, ice bath, drain. Spread on dehydrator trays. Dry at 55C for 8-12 hours until crisp. Rehydrate in soups and casseroles, or powder for adding nutrition to smoothies. Keeps: 12 months.
  • Fermentation (Lacto-fermented). Cut into small florets. Pack into jar with 2% brine (20g salt per litre water). Weigh down below brine surface. Ferment at room temperature 5-7 days. Refrigerate. Keeps: 3-6 months (refrigerated).
  • Pickling. Blanch small florets 2 minutes. Pack into sterilised jars with garlic, chilli, dill. Cover with hot brine (1 cup vinegar, 1 cup water, 1 tbsp salt). Water bath 10 minutes. Keeps: 12 months.

What broccoli costs in the shops right now, retailer by retailer, updated daily.

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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

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Common Questions About Broccoli

When do you plant broccoli in Australia?

It depends on your climate zone, not the calendar month alone. Planting months by zone:

Can you grow broccoli all year round in Cairns?

No. In the Tropical zone the planting months are Apr to Jul. Outside that window it either bolts, sulks or gets cut down by the weather.

When should I plant Broccoli in Cairns?

Dry season only. Start seed in trays in April and May and plant out from May to July. Summer planting will bolt.

What soil temperature do Broccoli need?

Broccoli germinate best when soil temperature is between 10°C and 30°C.

How do I know when Broccoli are ready to harvest?

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.

What are the best Broccoli varieties for Cairns?

Recommended varieties for the Tropical zone include: Green Magic (heat-tolerant hybrid), Summer Green, Belstar, Marathon.

What grows well with Broccoli?

Good companion plants for Broccoli include: Nasturtium, Dwarf Beans, Onion, Cucumber, Dill.

Are broccoli salt tolerant?

Only a little. Broccoli 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 Tropical zone, Cairns is its reference city.