When to plant Fennel
Florence fennel forms a crisp, anise-flavoured bulb at the base of feathery stalks. It bolts in heat and long days, so it's best as a fall crop in most regions. Note that it inhibits many neighbours — give it its own corner.
Companions: Best grown alone — it discourages most vegetable neighbours
How to grow Fennel
Fennel is best direct-sown straight into the garden, as it dislikes being transplanted. Give it full sun and space plants about 10 inches apart. It takes roughly 80 days from planting to its first harvest, so count that against your frost dates to be sure it can finish. It also supports a fall sowing for a second harvest. Classic companions include best grown alone — it discourages most vegetable neighbours.
Grower's tip: Grow bulbing (Florence) fennel in cool weather and mound soil around the swelling bulb to blanch it.
When to plant Fennel by USDA zone
Timing shifts with your climate — the same fennel goes in weeks earlier in a mild zone than a cold one. Find your zone below for its planting window, or open that zone's full calendar.
| Zone | When to plant |
|---|---|
| Zone 1a | Direct sow outdoors Jun 1–Jun 29 Direct sow outdoors Jun 6–Jun 20 |
| Zone 1b | Direct sow outdoors May 27–Jun 24 Direct sow outdoors Jun 11–Jun 25 |
| Zone 2a | Direct sow outdoors May 22–Jun 19 Direct sow outdoors Jun 16–Jun 30 |
| Zone 2b | Direct sow outdoors May 16–Jun 13 Direct sow outdoors Jun 23–Jul 7 |
| Zone 3a | Direct sow outdoors May 11–Jun 8 Direct sow outdoors Jun 30–Jul 14 |
| Zone 3b | Direct sow outdoors May 6–Jun 3 Direct sow outdoors Jul 4–Jul 18 |
| Zone 4a | Direct sow outdoors May 1–May 29 Direct sow outdoors Jul 10–Jul 24 |
| Zone 4b | Direct sow outdoors Apr 26–May 24 Direct sow outdoors Jul 14–Jul 28 |
| Zone 5a | Direct sow outdoors Apr 21–May 19 Direct sow outdoors Jul 23–Aug 6 |
| Zone 5b | Direct sow outdoors Apr 16–May 14 Direct sow outdoors Jul 27–Aug 10 |
| Zone 6a | Direct sow outdoors Apr 7–May 5 Direct sow outdoors Aug 8–Aug 22 |
| Zone 6b | Direct sow outdoors Apr 1–Apr 29 Direct sow outdoors Aug 16–Aug 30 |
| Zone 7a | Direct sow outdoors Mar 24–Apr 21 Direct sow outdoors Aug 24–Sep 7 |
| Zone 7b | Direct sow outdoors Mar 18–Apr 15 Direct sow outdoors Sep 1–Sep 15 |
| Zone 8a | Direct sow outdoors Mar 8–Apr 5 Direct sow outdoors Sep 9–Sep 23 |
| Zone 8b | Direct sow outdoors Mar 1–Mar 29 Direct sow outdoors Sep 16–Sep 30 |
| Zone 9a | Direct sow outdoors Feb 14–Mar 14 Direct sow outdoors Sep 26–Oct 10 |
| Zone 9b | Direct sow outdoors Feb 1–Mar 1 Direct sow outdoors Oct 6–Oct 20 |
| Zone 10a | Direct sow outdoors Jan 17–Feb 14 Direct sow outdoors Oct 19–Nov 2 |
| Zone 10b | Direct sow outdoors Jan 1–Jan 29 Direct sow outdoors Oct 22–Nov 5 |
| Zone 11a | Direct sow outdoors Dec 18–Jan 15 Direct sow outdoors Oct 22–Nov 5 |
| Zone 11b | Direct sow outdoors Dec 18–Jan 15 Direct sow outdoors Oct 22–Nov 5 |
| Zone 12a | Direct sow outdoors Dec 18–Jan 15 Direct sow outdoors Oct 22–Nov 5 |
| Zone 12b | Direct sow outdoors Dec 18–Jan 15 Direct sow outdoors Oct 22–Nov 5 |
| Zone 13a | Direct sow outdoors Dec 18–Jan 15 Direct sow outdoors Oct 22–Nov 5 |
| Zone 13b | Direct sow outdoors Dec 18–Jan 15 Direct sow outdoors Oct 22–Nov 5 |