When to Plant Fennel in Brisbane, Subtropical Guide
That soil figure is read off our own weather station in South East Queensland at 21:55 yesterday, not a model.
What this month normally looks like in Subtropical
In October the Subtropical zone normally runs 27°C by day and 15°C overnight, with about 77 mm of rain over 7 wet days. The coldest October night on record across the zone was -0.2°C, so a late frost is not out of the question. Averages 1991 to 2026, 33 postcodes, SILO.
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This Fennel guide is written for the Subtropical zone, which takes in Brisbane, the Gold Coast and the Sunshine Coast. Somewhere else? Your postcode picks the right one.
Not your zone? Cairns Sydney Melbourne Canberra Alice Springs Perth
Also handy: will it frost this week? and what grows in shade.
- Planting window
- Feb to Oct
- Days to harvest
- 60 days
- Sun
- Full sun
- Water
- Low
- Spacing
- 30 cm apart
- Soil pH
- 5.5–7.0
Herb fennel (common fennel) is a tall, feathery perennial grown for its anise-flavoured leaves, stems and seeds. NOT the same as Florence/bulb fennel (F. vulgare var. azoricum).
Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.
Photo: Wikimedia Commons
Planting Calendar for Subtropical
- Jan -
- Feb S/D
- Mar S/T/D
- Apr S/T/D
- May S/T/D
- Jun T/D
- Jul S (likely to bolt)
- Aug S/T/D (likely to bolt)
- Sep S/T/D (likely to bolt)
- Oct T (likely to bolt)
- Nov -
- Dec -
S = Seed Tray T = Transplant D = Direct Sow
Amber = likely to bolt if sown this month, it matures into heat or long days.
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How to Grow Fennel in Subtropical Australia
- Soil
- Any well-drained soil. Tolerant of poor soils. Drought tolerant once established.
- Salt
- Moderately sensitive. Copes with a little salt, but the harvest drops on salty bore water.
- pH Range
- 5.5-7.0
- Sunlight
- Full sun.
- Spacing
- 30cm apart, 60cm between rows
- Watering
- Low water needs once established. Water regularly when young. Very drought tolerant as a perennial.
- Good companions
- Lettuce, Cucumber, Peas, Sage, Chicory and Radicchio
- Keep away from
- Amaranth, Angelica, Broad Beans, Cape Gooseberry, Capsicum, Carrot, Cherry, Chickpeas, Chilli peppers, Climbing Beans, Coriander, Dill, Dwarf Beans, Eggplant, Kohlrabi, Lemongrass, Quinoa, Snake Beans, Strawberry, Tomatillo, Tomato
Subtropical Growing Tips for Fennel
Recommended Varieties
- Common fennel
- Bronze fennel
- Sweet fennel
Key Challenges
- Can become weedy. Deadhead to prevent spread
- Self-sows aggressively
Pro Tips
- WARNING: Herb fennel is an environmental weed in parts of QLD and NSW. Deadhead religiously.
- Bronze fennel is ornamental and equally useful culinarily
- Keep away from vegetable garden due to allelopathic effects
Pests and problems for Fennel in Subtropical
Organic prevention (Aphids): Healthy plants outgrow damage.
Harvesting Fennel
When ready: Harvest leaves anytime once plant is established. Seeds ready when brown on plant.
How to harvest: Snip feathery fronds as needed. Cut seed heads when brown and dry in paper bags. Harvest young stems for cooking.
Storing and preserving fennel
How to keep it
- Drying seeds. Dry seed heads in paper bags for 2-3 weeks. Store whole seeds. Toast before grinding for best flavour. Keeps: 2-3 years whole seeds.
- Freezing fronds. Chop fronds finely, freeze in ice cube trays with water or oil. Keeps: 6 months.
- Fennel pollen. Harvest flower heads when bright yellow and heavy with pollen. Dry on paper in dark room for 3-5 days. Sift pollen from flowers. Extraordinary flavour. The saffron of the herb world. Keeps: 12 months in airtight jar, refrigerated.
What fennel costs in the shops right now, retailer by retailer, updated daily.
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 Fennel
When do you plant fennel in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): Apr to Aug Likely to bolt if sown in June, July and August.
- Subtropical (Brisbane): Feb to Oct Likely to bolt if sown in July, August, September and October.
- Warm Temperate (Sydney): Jan to Apr, Aug to Dec Likely to bolt if sown in September, October and November.
- Cool Temperate (Melbourne): Jan to Mar, Dec
- Cold / Highland (Canberra): Jan, Oct to Dec Likely to bolt if sown in October and November.
- Arid / Semi-Arid (Alice Springs): Feb to May
- Mediterranean (Perth): Mar to May, Aug to Nov Likely to bolt if sown in September, October and November.
Can you grow fennel all year round in Brisbane?
No. In the Subtropical zone the planting months are Feb to Oct. Outside that window it either bolts, sulks or gets cut down by the weather. Likely to bolt if sown in July, August, September and October.
When should I plant Fennel in Brisbane?
Herb fennel grows readily here as a hardy perennial and self-seeds freely, so remove flower heads before seed drops. For bulbs, grow Florence fennel from an autumn sowing.
What soil temperature do Fennel need?
Fennel germinate best when soil temperature is between 10°C and 25°C.
How do I know when Fennel are ready to harvest?
Harvest leaves anytime once plant is established. Seeds ready when brown on plant.
What are the best Fennel varieties for Brisbane?
Recommended varieties for the Subtropical zone include: Common fennel, Bronze fennel, Sweet fennel.
What grows well with Fennel?
Good companion plants for Fennel include: Lettuce, Cucumber, Peas, Sage, Chicory and Radicchio.
Are fennel salt tolerant?
Only a little. 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 Subtropical zone, Brisbane is its reference city.