When to plant fennel (bulb) in Iowa
Iowa spans USDA zones 5a–6a, so the right time to plant fennel (bulb) shifts by weeks across the state. The window to transplant seedlings outdoors runs from about March 29 in Fort Madison to April 17 in Spencer — below are local dates for 42 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Des Moines | 5b | April 18 | October 20 | April 4 – April 18 |
| Cedar Rapids | 5b | April 27 | October 11 | April 13 – April 27 |
| Davenport | 5b | April 19 | October 22 | April 5 – April 19 |
| Sioux City | 5a | April 29 | October 7 | April 15 – April 29 |
| Iowa City | 5b | April 21 | October 18 | April 7 – April 21 |
| Ankeny | 5b | April 23 | October 15 | April 9 – April 23 |
| West Des Moines | 5b | April 18 | October 20 | April 4 – April 18 |
| Ames | 5b | April 26 | October 8 | April 12 – April 26 |
Fennel (Bulb) in Iowa: FAQ
When can I plant fennel (bulb) in Iowa?
Across Iowa, the time to transplant fennel (bulb) spans roughly March 29 in Fort Madison to April 17 in Spencer, each following that city's local frost dates.
Does the fennel (bulb) planting date vary across Iowa?
Yes. Iowa publishes 42 cities with their own frost dates, so the right fennel (bulb) planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
How long does fennel (bulb) take to grow in Iowa?
Fennel (Bulb) takes about 65–90 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
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