When to Plant Florence Fennel in Cairns, Tropical Guide
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.
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This Florence Fennel 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 12 weeks
- Sun
- Full sun
- Water
- Regular
- Spacing
- 15 cm apart
- Soil pH
- 6.0–7.0
Foeniculum vulgare Azoricum Group. Bulb fennel, distinct from perennial herb fennel. Grown for swollen leaf bases; steady moisture and minimal root disturbance reduce bolting.
Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.
Photo: Wikimedia Commons
Planting Calendar for Tropical
- Jan -
- Feb -
- Mar -
- Apr D
- May D
- Jun D
- Jul D
- Aug -
- Sep -
- Oct -
- Nov -
- Dec -
S = Seed Tray T = Transplant D = Direct Sow
Want a nudge when it is sowing time?
One email a week with what is worth planting in the Tropical zone right now, Florence Fennel included, plus which veg has jumped in price at the supermarket. Free, and you can stop it in one click.
How to Grow Florence Fennel in Tropical Australia
- Soil
- Rich, fertile, light organic loam
- Salt
- Moderately sensitive. Copes with a little salt, but the harvest drops on salty bore water.
- pH Range
- 6.0-7.0
- Sunlight
- Full sun, at least 6 hours of direct sun a day
- Spacing
- 15cm apart, 45cm between rows
- Watering
- Water deeply and regularly, more in hot weather. Check the soil about 5 cm down, and water early morning or late afternoon to avoid leaf fungal disease.
- Good companions
- Lettuce, Cucumber, Peas, Sage, Endive
Tropical Growing Tips for Florence Fennel
Recommended Varieties
- Romanesco (Florence fennel)
- Doux de Florence (Florence fennel)
Key Challenges
- Common Garden Snail: Introduced snail with a tan spiral shell
- Slugs: Soft-bodied shell-less molluscs that feed at night on seedlings and leafy vegetables
- Slugs and Snails: Eat young seedlings and tender leaves
- Root rot from overwatering: Plants die and bulbs rot
Pro Tips
- Work rich compost or well-rotted manure into soil prior to sowing; feed with liquid organic fertiliser every 2 to 3 weeks during bulb swelling
- Apply organic straw mulch around plants to keep soil cool, retain moisture, and suppress weed growth
Pests and problems for Florence Fennel in Tropical
- Common Garden Snail Common Garden Snail: Introduced snail with a tan spiral shell Watch
- Slugs Slugs: Soft-bodied shell-less molluscs that feed at night on seedlings and leafy vegetables Watch
- Aphids Watch
- Root rot from overwatering Use free-draining soil, water evenly and avoid waterlogging. Watch
- Bolting (not a disease) Sow in the cool season, avoid root disturbance and water evenly. Watch
Harvesting Florence Fennel
When ready: Swollen bulb base reaches tennis-ball size (roughly 7 to 10 cm across) before flower shoots emerge
How to harvest: Cut the swollen bulb at ground level just above the taproot with a sharp knife
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
Common Questions About Florence Fennel
When do you plant florence fennel in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): Apr to Jul
- Subtropical (Brisbane): Mar to May
- Warm Temperate (Sydney): Feb to May, Sep to Oct
- Cool Temperate (Melbourne): Jan to Feb, Sep to Dec
- Cold / Highland (Canberra): Jan, Oct to Dec
- Arid / Semi-Arid (Alice Springs): Mar to Apr, Aug
- Mediterranean (Perth): Feb to May, Aug to Sep
Can you grow florence fennel 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 Florence Fennel in Cairns?
Supplier tropical sowing window.
What soil temperature do Florence Fennel need?
Florence Fennel germinate best when soil temperature is between 15°C and 22°C.
How do I know when Florence Fennel are ready to harvest?
Swollen bulb base reaches tennis-ball size (roughly 7 to 10 cm across) before flower shoots emerge
What are the best Florence Fennel varieties for Cairns?
Recommended varieties for the Tropical zone include: Romanesco (Florence fennel), Doux de Florence (Florence fennel).
What grows well with Florence Fennel?
Good companion plants for Florence Fennel include: Lettuce, Cucumber, Peas, Sage, Endive.
Are florence fennel salt tolerant?
Only a little. Florence fennel 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.