Des Moines, IA planting zone & frost dates
Des Moines is in USDA hardiness zone 5b. The last spring frost usually comes around April 18 and the first fall frost around October 20, for a growing season of about 184 days.
Planting calendar for Des Moines
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 25 (8 weeks before the average first fall frost on Oct 20).
Useful for zone 5b 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 4 | Apr 18 | May 2 |
| First 32°F frost in fall is before | Nov 1 | Oct 20 | Oct 4 |
How to read it: in spring there is a 10% chance of a frost after May 2, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 4. A hard freeze (28°F) usually ends around April 8.
Hardiness zone by ZIP code in Des Moines
- 50301 zone 5b
- 50302 zone 5b
- 50303 zone 5b
- 50304 zone 5b
- 50305 zone 5b
- 50306 zone 5b
- 50307 zone 5b
- 50308 zone 5b
- 50309 zone 5b
- 50310 zone 5b
- 50311 zone 5b
- 50312 zone 5b
- 50313 zone 5b
- 50314 zone 5b
- 50315 zone 5b
- 50316 zone 5b
- 50317 zone 5b
- 50318 zone 5b
- 50319 zone 5b
- 50320 zone 5b
- 50321 zone 5b
- 50328 zone 5b
- 50329 zone 5b
- 50330 zone 5b
- 50331 zone 5b
- 50332 zone 5b
- 50333 zone 5b
- 50334 zone 5b
- 50335 zone 5b
- 50336 zone 5b
- 50339 zone 5b
- 50340 zone 5b
- 50359 zone 5b
- 50360 zone 5b
- 50361 zone 5b
- 50362 zone 5b
- 50363 zone 5b
- 50364 zone 5b
- 50367 zone 5b
- 50368 zone 5b
- 50369 zone 5b
- 50380 zone 5b
- 50381 zone 5b
- 50391 zone 5b
- 50392 zone 5b
- 50393 zone 5b
- 50394 zone 5b
- 50395 zone 5b
- 50396 zone 5b
- 50936 zone 5b
- 50940 zone 5b
- 50947 zone 5b
- 50950 zone 5b
- 50980 zone 5b
- 50981 zone 5b
- 50982 zone 5b
- 50983 zone 5b
Nearby cities
Questions
What growing zone is Des Moines, IA?
Des Moines is in USDA Plant Hardiness Zone 5b (average extreme winter low -15°F to -10°F), according to the USDA 2023 map.
When is the last frost in Des Moines?
The average last spring frost (32°F) in Des Moines is April 18. There is still a 10% chance of frost until May 2.
When can I plant tomatoes in Des Moines?
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 Des Moines Intl Ap, IA (USW00014933), 8.3 km (5.2 mi) from the city center, elevation 292 m, based on 26 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.