When to Plant Onions in Michigan
In Michigan, the time to plant onions outside runs from Mar 22 – Apr 5 in Port Huron to Apr 10 – Apr 24 in Burton. In Detroit, it's Mar 30 – Apr 13. The average last spring frost differs by about 3 weeks across the state (Apr 19 in Port Huron, May 8 in Burton), 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 Michigan by city
| City | Zone | Start indoors | Plant outside |
|---|---|---|---|
| Ann Arbor | 6a | Feb 10 – Feb 24 | Apr 7 – Apr 21 |
| Battle Creek | 6a | Feb 5 – Feb 19 | Apr 2 – Apr 16 |
| Bay City | 6a | Feb 2 – Feb 16 | Mar 30 – Apr 13 |
| Burton | 6a | Feb 13 – Feb 27 | Apr 10 – Apr 24 |
| Dearborn | 6b | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Dearborn Heights | 6b | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Detroit | 6b | Feb 2 – Feb 16 | Mar 30 – Apr 13 |
| East Lansing | 6a | Feb 3 – Feb 17 | Mar 31 – Apr 14 |
| Eastpointe | 6b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Farmington Hills | 6a | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Flint | 6a | Feb 8 – Feb 22 | Apr 5 – Apr 19 |
| Grand Rapids | 6a | Feb 11 – Feb 25 | Apr 8 – Apr 22 |
| Holland | 6b | Feb 3 – Feb 17 | Mar 31 – Apr 14 |
| Jackson | 6a | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Kalamazoo | 6a | Feb 3 – Feb 17 | Mar 31 – Apr 14 |
| Kentwood | 6a | Feb 5 – Feb 19 | Apr 2 – Apr 16 |
| Lansing | 6a | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Lincoln Park | 6b | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Livonia | 6b | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Madison Heights | 6b | Jan 27 – Feb 10 | Mar 24 – Apr 7 |
| Midland | 6a | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Muskegon | 6b | Feb 5 – Feb 19 | Apr 2 – Apr 16 |
| Novi | 6a | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Oak Park | 6b | Feb 2 – Feb 16 | Mar 30 – Apr 13 |
| Pontiac | 6a | Feb 1 – Feb 15 | Mar 29 – Apr 12 |
| Port Huron | 6b | Jan 25 – Feb 8 | Mar 22 – Apr 5 |
| Portage | 6a | Feb 3 – Feb 17 | Mar 31 – Apr 14 |
| Rochester Hills | 6a | Feb 1 – Feb 15 | Mar 29 – Apr 12 |
| Roseville | 6b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Royal Oak | 6b | Jan 27 – Feb 10 | Mar 24 – Apr 7 |
| Saginaw | 6a | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Southfield | 6b | Feb 6 – Feb 20 | Apr 3 – Apr 17 |
| Southgate | 6b | Jan 26 – Feb 9 | Mar 23 – Apr 6 |
| St. Clair Shores | 6b | Feb 4 – Feb 18 | Apr 1 – Apr 15 |
| Sterling Heights | 6b | Feb 5 – Feb 19 | Apr 2 – Apr 16 |
| Taylor | 6b | Jan 26 – Feb 9 | Mar 23 – Apr 6 |
| Troy | 6b | Feb 1 – Feb 15 | Mar 29 – Apr 12 |
| Warren | 6b | Jan 27 – Feb 10 | Mar 24 – Apr 7 |
| Westland | 6b | Jan 26 – Feb 9 | Mar 23 – Apr 6 |
| Wyoming | 6a | Feb 11 – Feb 25 | Apr 8 – Apr 22 |
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 Michigan, or the general guide to when to plant onions.
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