When to Plant Onions in Kansas
In Kansas, the time to plant onions outside runs from Mar 7 – Mar 21 in Kansas City to Mar 31 – Apr 14 in Garden City. In Wichita, it's Mar 14 – Mar 28. The average last spring frost differs by about 3 weeks across the state (Apr 4 in Kansas City, Apr 28 in Garden City), so use the dates for the town nearest you.
Onions are cold-hardy. Plant sets or transplants early so they grow leaves before long summer days trigger bulbing.
- Start indoors: 10–12 weeks before the last frost.
- Plant outside: 2–4 weeks before the last frost.
Onions planting dates in Kansas by city
| City | Zone | Start indoors | Plant outside |
|---|---|---|---|
| Andover | 7a | Jan 16 – Jan 30 | Mar 13 – Mar 27 |
| Arkansas City | 7a | Jan 17 – Jan 31 | Mar 14 – Mar 28 |
| Atchison | 6a | Jan 17 – Jan 31 | Mar 14 – Mar 28 |
| Bel Aire | 7a | Jan 16 – Jan 30 | Mar 13 – Mar 27 |
| Derby | 7a | Jan 20 – Feb 3 | Mar 17 – Mar 31 |
| Dodge City | 6b | Jan 27 – Feb 10 | Mar 24 – Apr 7 |
| El Dorado | 6b | Jan 19 – Feb 2 | Mar 16 – Mar 30 |
| Emporia | 6b | Jan 21 – Feb 4 | Mar 18 – Apr 1 |
| Garden City | 6b | Feb 3 – Feb 17 | Mar 31 – Apr 14 |
| Gardner | 6b | Jan 19 – Feb 2 | Mar 16 – Mar 30 |
| Great Bend | 6b | Jan 30 – Feb 13 | Mar 27 – Apr 10 |
| Hays | 6b | Jan 25 – Feb 8 | Mar 22 – Apr 5 |
| Haysville | 7a | Jan 20 – Feb 3 | Mar 17 – Mar 31 |
| Hutchinson | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Junction City | 6b | Jan 18 – Feb 1 | Mar 15 – Mar 29 |
| Kansas City | 6b | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Lansing | 6b | Jan 25 – Feb 8 | Mar 22 – Apr 5 |
| Lawrence | 6b | Jan 18 – Feb 1 | Mar 15 – Mar 29 |
| Leavenworth | 6b | Jan 18 – Feb 1 | Mar 15 – Mar 29 |
| Leawood | 6b | Jan 14 – Jan 28 | Mar 11 – Mar 25 |
| Lenexa | 6b | Jan 16 – Jan 30 | Mar 13 – Mar 27 |
| Liberal | 6b | Jan 26 – Feb 9 | Mar 23 – Apr 6 |
| Manhattan | 6a | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| McPherson | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Merriam | 6b | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Mission | 6b | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Newton | 6b | Jan 20 – Feb 3 | Mar 17 – Mar 31 |
| Olathe | 6b | Jan 16 – Jan 30 | Mar 13 – Mar 27 |
| Ottawa | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Overland Park | 6b | Jan 16 – Jan 30 | Mar 13 – Mar 27 |
| Park City | 7a | Jan 16 – Jan 30 | Mar 13 – Mar 27 |
| Parsons | 7a | Jan 17 – Jan 31 | Mar 14 – Mar 28 |
| Pittsburg | 7a | Jan 13 – Jan 27 | Mar 10 – Mar 24 |
| Prairie Village | 6b | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Salina | 6b | Jan 24 – Feb 7 | Mar 21 – Apr 4 |
| Shawnee | 6b | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Spring Hill | 6b | Jan 19 – Feb 2 | Mar 16 – Mar 30 |
| Topeka | 6b | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Wichita | 7a | Jan 17 – Jan 31 | Mar 14 – Mar 28 |
| Winfield | 7a | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
Calculated from each town's average (50%) frost dates, from the nearest NOAA station (1991–2020). Typical dates for the 2027 planting season, based on NOAA's 1991–2020 averages. They are long-term odds, not a forecast: always check your local forecast before planting. Zones: 2023 USDA Plant Hardiness Zone Map (USDA-ARS and Oregon State University). Not the official map; see planthardiness.ars.usda.gov.
See all frost dates in Kansas, or the general guide to when to plant onions.
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