Coldwater, MI planting zone & frost dates
Coldwater is in USDA hardiness zone 6a. The last spring frost usually comes around May 2 and the first fall frost around October 13, for a growing season of about 163 days.
Planting calendar for Coldwater
Dates are counted from the average last spring frost (May 2) 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 7 – Mar 21 Transplant outdoors: May 9 – May 16 |
| Peppers | Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: May 16 – May 23 |
| Eggplant | Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: May 16 – May 23 |
| Broccoli | Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: Apr 4 – Apr 18 |
| Cabbage | Start seeds indoors: Feb 21 – Mar 7 Transplant outdoors: Apr 4 – Apr 18 |
| Onions (sets) | Plant outdoors: Apr 4 – Apr 18 |
| Peas | Sow outdoors: Mar 21 – Apr 4 |
| Spinach | Sow outdoors: Mar 21 – Apr 4 |
| Lettuce | Sow outdoors: Apr 4 – Apr 18 |
| Carrots | Sow outdoors: Apr 4 – Apr 18 |
| Potatoes | Plant outdoors: Apr 4 – Apr 18 |
| Beans | Sow outdoors: May 9 – May 16 |
| Sweet corn | Sow outdoors: May 9 – May 16 |
| Cucumbers | Sow outdoors: May 9 – May 16 |
| Squash & zucchini | Sow outdoors: May 9 – May 16 |
| Basil | Start seeds indoors: Mar 21 – Apr 4 Transplant outdoors: May 9 – May 16 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 18 (8 weeks before the average first fall frost on Oct 13).
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
As an Amazon Associate, FrostZoneMap earns from qualifying purchases, at no extra cost to you.
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 18 | May 2 | May 18 |
| First 32°F frost in fall is before | Oct 30 | Oct 13 | Sep 30 |
How to read it: in spring there is a 10% chance of a frost after May 18, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 30. A hard freeze (28°F) usually ends around April 21.
Hardiness zone by ZIP code in Coldwater
- 49036 zone 6a
Nearby cities
Questions
What growing zone is Coldwater, MI?
Coldwater 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 Coldwater?
The average last spring frost (32°F) in Coldwater is May 2. There is still a 10% chance of frost until May 18.
When can I plant tomatoes in Coldwater?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 9 – May 16. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Coldwater St School, MI (USC00201675), 2.5 km (1.6 mi) from the city center, elevation 300 m, based on 28 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.