Dearborn, MI planting zone & frost dates
Dearborn is in USDA hardiness zone 6b. The last spring frost usually comes around April 27 and the first fall frost around October 25, for a growing season of about 181 days.
Planting calendar for Dearborn
Dates are counted from the average last spring frost (April 27) 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: Mar 2 – Mar 16 Transplant outdoors: May 4 – May 11 |
| Peppers | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: May 11 – May 18 |
| Eggplant | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: May 11 – May 18 |
| Broccoli | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: Mar 30 – Apr 13 |
| Cabbage | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: Mar 30 – Apr 13 |
| Onions (sets) | Plant outdoors: Mar 30 – Apr 13 |
| Peas | Sow outdoors: Mar 16 – Mar 30 |
| Spinach | Sow outdoors: Mar 16 – Mar 30 |
| Lettuce | Sow outdoors: Mar 30 – Apr 13 |
| Carrots | Sow outdoors: Mar 30 – Apr 13 |
| Potatoes | Plant outdoors: Mar 30 – Apr 13 |
| Beans | Sow outdoors: May 4 – May 11 |
| Sweet corn | Sow outdoors: May 4 – May 11 |
| Cucumbers | Sow outdoors: May 4 – May 11 |
| Squash & zucchini | Sow outdoors: May 4 – May 11 |
| Basil | Start seeds indoors: Mar 16 – Mar 30 Transplant outdoors: May 4 – May 11 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 30 (8 weeks before the average first fall frost on Oct 25).
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 12 | Apr 27 | May 11 |
| First 32°F frost in fall is before | Nov 7 | Oct 25 | Oct 10 |
How to read it: in spring there is a 10% chance of a frost after May 11, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 10. A hard freeze (28°F) usually ends around April 15.
Hardiness zone by ZIP code in Dearborn
- 48120 zone 6b
- 48121 zone 6b
- 48123 zone 6b
- 48124 zone 6b
- 48126 zone 6b
- 48128 zone 6b
Nearby cities
- Melvindale zone 6b, last frost May 1
- Lincoln Park zone 6b, last frost May 1
- Allen Park zone 6b, last frost May 1
- Dearborn Heights zone 6b, last frost May 1
- Southgate zone 6b, last frost Apr 20
- Wyandotte zone 6b, last frost May 1
- Highland Park zone 6b, last frost Apr 21
- Taylor zone 6b, last frost Apr 20
Questions
What growing zone is Dearborn, MI?
Dearborn is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°F), according to the USDA 2023 map.
When is the last frost in Dearborn?
The average last spring frost (32°F) in Dearborn is April 27. There is still a 10% chance of frost until May 11.
When can I plant tomatoes in Dearborn?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 4 – May 11. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Dearborn #2, MI (USC00202016), 2.7 km (1.7 mi) from the city center, elevation 184 m, based on 14 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.