Forest Hills, MI planting zone & frost dates
Forest Hills is in USDA hardiness zone 6a. The last spring frost usually comes around April 29 and the first fall frost around October 20, for a growing season of about 174 days.
Planting calendar for Forest Hills
Dates are counted from the average last spring frost (April 29) 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 4 – Mar 18 Transplant outdoors: May 6 – May 13 |
| Peppers | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: May 13 – May 20 |
| Eggplant | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: May 13 – May 20 |
| Broccoli | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: Apr 1 – Apr 15 |
| Cabbage | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: Apr 1 – Apr 15 |
| Onions (sets) | Plant outdoors: Apr 1 – Apr 15 |
| Peas | Sow outdoors: Mar 18 – Apr 1 |
| Spinach | Sow outdoors: Mar 18 – Apr 1 |
| Lettuce | Sow outdoors: Apr 1 – Apr 15 |
| Carrots | Sow outdoors: Apr 1 – Apr 15 |
| Potatoes | Plant outdoors: Apr 1 – Apr 15 |
| Beans | Sow outdoors: May 6 – May 13 |
| Sweet corn | Sow outdoors: May 6 – May 13 |
| Cucumbers | Sow outdoors: May 6 – May 13 |
| Squash & zucchini | Sow outdoors: May 6 – May 13 |
| Basil | Start seeds indoors: Mar 18 – Apr 1 Transplant outdoors: May 6 – May 13 |
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 6a 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 14 | Apr 29 | May 15 |
| First 32°F frost in fall is before | Nov 2 | Oct 20 | Oct 4 |
How to read it: in spring there is a 10% chance of a frost after May 15, 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 16.
Nearby cities
- East Grand Rapids zone 6a, last frost May 6
- Northview zone 6a, last frost May 6
- Grand Rapids zone 6a, last frost May 6
- Kentwood zone 6a, last frost May 6
- Comstock Park zone 6a, last frost May 6
- Cutlerville zone 6a, last frost Apr 30
- Wyoming zone 6a, last frost May 6
- Grandville zone 6a, last frost May 6
Questions
What growing zone is Forest Hills, MI?
Forest Hills is in USDA Plant Hardiness Zone 6a (average extreme winter low -10°F to -5°F), according to the USDA 2023 map.
When is the last frost in Forest Hills?
The average last spring frost (32°F) in Forest Hills is April 29. There is still a 10% chance of frost until May 15.
When can I plant tomatoes in Forest Hills?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 6 – May 13. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Grand Rapids, MI (USW00094860), 8.6 km (5.3 mi) from the city center, elevation 237 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.