Detroit, MI planting zone & frost dates
Detroit is in USDA hardiness zone 6b. The last spring frost usually comes around April 21 and the first fall frost around October 31, for a growing season of about 190 days.
Planting calendar for Detroit
Dates are counted from the average last spring frost (April 21) 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 24 – Mar 10 Transplant outdoors: Apr 28 – May 5 |
| Peppers | Start seeds indoors: Feb 10 – Feb 24 Transplant outdoors: May 5 – May 12 |
| Eggplant | Start seeds indoors: Feb 10 – Feb 24 Transplant outdoors: May 5 – May 12 |
| Broccoli | Start seeds indoors: Feb 10 – Feb 24 Transplant outdoors: Mar 24 – Apr 7 |
| Cabbage | Start seeds indoors: Feb 10 – Feb 24 Transplant outdoors: Mar 24 – Apr 7 |
| Onions (sets) | Plant outdoors: Mar 24 – Apr 7 |
| Peas | Sow outdoors: Mar 10 – Mar 24 |
| Spinach | Sow outdoors: Mar 10 – Mar 24 |
| Lettuce | Sow outdoors: Mar 24 – Apr 7 |
| Carrots | Sow outdoors: Mar 24 – Apr 7 |
| Potatoes | Plant outdoors: Mar 24 – Apr 7 |
| Beans | Sow outdoors: Apr 28 – May 5 |
| Sweet corn | Sow outdoors: Apr 28 – May 5 |
| Cucumbers | Sow outdoors: Apr 28 – May 5 |
| Squash & zucchini | Sow outdoors: Apr 28 – May 5 |
| Basil | Start seeds indoors: Mar 10 – Mar 24 Transplant outdoors: Apr 28 – May 5 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 5 (8 weeks before the average first fall frost on Oct 31).
Useful for zone 6b 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 7 | Apr 21 | May 6 |
| First 32°F frost in fall is before | Nov 11 | Oct 31 | Oct 17 |
How to read it: in spring there is a 10% chance of a frost after May 6, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 17. A hard freeze (28°F) usually ends around April 8.
Hardiness zone by ZIP code in Detroit
- 48201 zone 6b
- 48202 zone 6b
- 48204 zone 6b
- 48205 zone 6b
- 48206 zone 6b
- 48207 zone 6b
- 48208 zone 6b
- 48209 zone 6b
- 48210 zone 6b
- 48211 zone 6b
- 48213 zone 6b
- 48214 zone 6b
- 48215 zone 6b
- 48216 zone 6b
- 48217 zone 6b
- 48219 zone 6b
- 48221 zone 6b
- 48222 zone 6b
- 48223 zone 6b
- 48224 zone 6b
- 48226 zone 6b
- 48227 zone 6b
- 48228 zone 6b
- 48231 zone 6b
- 48232 zone 6b
- 48233 zone 6b
- 48234 zone 6b
- 48235 zone 6b
- 48238 zone 6b
- 48242 zone 6b
- 48243 zone 6b
- 48244 zone 6b
- 48255 zone 6b
- 48260 zone 6b
- 48264 zone 6b
- 48265 zone 6b
- 48266 zone 6b
- 48267 zone 6b
- 48268 zone 6b
- 48269 zone 6b
- 48272 zone 6b
- 48275 zone 6b
- 48277 zone 6b
- 48278 zone 6b
- 48279 zone 6b
- 48288 zone 6b
Nearby cities
- Hamtramck zone 6b, last frost Apr 21
- Highland Park zone 6b, last frost Apr 21
- Grosse Pointe Park zone 6b, last frost Apr 29
- Dearborn zone 6b, last frost Apr 27
- Melvindale zone 6b, last frost May 1
- Hazel Park zone 6b, last frost Apr 21
- Lincoln Park zone 6b, last frost May 1
- Ferndale zone 6b, last frost Apr 21
Questions
What growing zone is Detroit, MI?
Detroit 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 Detroit?
The average last spring frost (32°F) in Detroit is April 21. There is still a 10% chance of frost until May 6.
When can I plant tomatoes in Detroit?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 28 – May 5. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Detroit City Ap, MI (USW00014822), 9.1 km (5.7 mi) from the city center, elevation 191 m, based on 29 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.