Council Bluffs, IA planting zone & frost dates
Council Bluffs is in USDA hardiness zone 6a. The last spring frost usually comes around April 18 and the first fall frost around October 21, for a growing season of about 185 days.
Planting calendar for Council Bluffs
Dates are counted from the average last spring frost (April 18) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: Apr 25 – May 2 |
| Peppers | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: May 2 – May 9 |
| Eggplant | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: May 2 – May 9 |
| Broccoli | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: Mar 21 – Apr 4 |
| Cabbage | Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: Mar 21 – Apr 4 |
| Onions (sets) | Plant outdoors: Mar 21 – Apr 4 |
| Peas | Sow outdoors: Mar 7 – Mar 21 |
| Spinach | Sow outdoors: Mar 7 – Mar 21 |
| Lettuce | Sow outdoors: Mar 21 – Apr 4 |
| Carrots | Sow outdoors: Mar 21 – Apr 4 |
| Potatoes | Plant outdoors: Mar 21 – Apr 4 |
| Beans | Sow outdoors: Apr 25 – May 2 |
| Sweet corn | Sow outdoors: Apr 25 – May 2 |
| Cucumbers | Sow outdoors: Apr 25 – May 2 |
| Squash & zucchini | Sow outdoors: Apr 25 – May 2 |
| Basil | Start seeds indoors: Mar 7 – Mar 21 Transplant outdoors: Apr 25 – May 2 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 26 (8 weeks before the average first fall frost on Oct 21).
Useful for zone 6a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Cold frame / mini greenhouse — adds weeks to a short season
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 5 | Apr 18 | Apr 30 |
| First 32°F frost in fall is before | Nov 1 | Oct 21 | Oct 6 |
How to read it: in spring there is a 10% chance of a frost after April 30, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 6. A hard freeze (28°F) usually ends around April 8.
Hardiness zone by ZIP code in Council Bluffs
- 51501 zone 5b
- 51502 zone 6a
- 51503 zone 6a
Nearby cities
- Sioux City zone 5a, last frost Apr 29
- Storm Lake zone 5a, last frost Apr 25
- Waukee zone 5b, last frost Apr 19
- Spencer zone 5a, last frost May 1
- Fort Dodge zone 5a, last frost Apr 28
- Grimes zone 5b, last frost Apr 19
- Boone zone 5a, last frost Apr 28
- Clive zone 5b, last frost Apr 18
Questions
What growing zone is Council Bluffs, IA?
Council Bluffs is in USDA Plant Hardiness Zone 6a (average extreme winter low -10°F to -5°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 5b.
When is the last frost in Council Bluffs?
The average last spring frost (32°F) in Council Bluffs is April 18. There is still a 10% chance of frost until April 30.
When can I plant tomatoes in Council Bluffs?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 25 – May 2. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Omaha Eppley Airfield, NE (USW00014942), 6.3 km (3.9 mi) from the city center, elevation 299 m, based on 30 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.