When to Plant Fennel
Fennel is a half-hardy cool-season vegetable. It takes light frosts but not a hard freeze.
Sow it outdoors from 2 weeks before the last spring frost to 2 weeks after it. For a fall crop, sow 11 to 14 weeks before the first fall frost. The first harvest comes about 75 to 100 days after sowing.
Example dates
The same rules in dates for three climates, using typical frost dates. Enter your ZIP code above for the dates where you live.
| Task | Last frost Mar 15first Nov 15 | Last frost Apr 15first Oct 25 | Last frost May 15first Sep 30 |
|---|---|---|---|
| Sow outdoors | Mar 1 – 29 | Apr 1 – 29 | May 1 – 29 |
| Harvest | May 15 – Jun 5 | Jun 15 – Jul 6 | Jul 15 – Aug 5 |
| Fall: Sow outdoors | Aug 9 – 30 | Jul 19 – Aug 9 | Jun 24 – Jul 15 |
| Fall: Harvest | Oct 23 – Nov 13 | Oct 2 – 23 | Sep 7 – 28 |
Growing fennel
Florence fennel dislikes transplanting and bolts under stress; cut the bulb when it is about tennis-ball size.
- Spacing: 10 in apart, in rows 24 in apart. In a raised bed, 1 per sq ft at square-foot spacing.
- Days to harvest: 75 to 100 from sowing, then about 3 weeks of picking.
- Rotation: fennel is in the carrot family. Plant it where nothing from that family grew in the last two years. See crop rotation.
- Traditional companions: head lettuce, leaf lettuce, romaine lettuce. See companion plants for fennel.
- Usually kept apart from: cherry tomato, eggplant, tomato.
Plan your beds with these dates
Draw your beds, tap squares to plant fennel and everything else, and get every crop's dates for your ZIP code in one calendar. Free, in your browser.
Open the garden plannerQuestions
Can fennel go in before the last frost?
Yes. Fennel is half-hardy: sow it from 2 weeks before the last spring frost to 2 weeks after it.
How long does fennel take to grow?
About 75 to 100 days from sowing to the first harvest, which then lasts about 3 weeks. Varieties differ: check the seed packet.
Can I grow fennel in fall?
Yes. Sow 11 to 14 weeks before the first fall frost. Enter your ZIP code above for the dates where you live.
More planting dates
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020 (annual/seasonal, by station: freeze dates at 32 °F)
- NC State Extension: Extension Gardener Handbook, Chapter 16: Vegetable Gardening
- WSU Extension: Pacific Northwest Gardener's Handbook, Chapter 7: Vegetable Gardening
- Iowa State: Growing, Harvesting, and Drying Herbs
- University of California Cooperative Extension Master Gardeners (UC ANR): Use and Culture of Culinary Herbs (table from the California Master Gardener Handbook)
- Texas AgriLife Extension Service, Texas A&M System (J. Masabni): Growing Herbs (E-561, 2009)
- UC Master Gardener Program, UC ANR: Companion Planting Chart: Companion Planting for Edible Crops
- Penn State Extension: Herbs Make Good Plant Partners and Companions
- University of Arizona Cooperative Extension, Yavapai County: The Art of Companion Planting (Master Gardener presentation, 2023)