Richfield, WI planting zone & frost dates
Richfield is in USDA hardiness zone 5b. The last spring frost usually comes around April 30 and the first fall frost around October 16, for a growing season of about 167 days.
Planting calendar for Richfield
Dates are counted from the average last spring frost (April 30) 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 5 – Mar 19 Transplant outdoors: May 7 – May 14 |
| Peppers | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: May 14 – May 21 |
| Eggplant | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: May 14 – May 21 |
| Broccoli | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: Apr 2 – Apr 16 |
| Cabbage | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: Apr 2 – Apr 16 |
| Onions (sets) | Plant outdoors: Apr 2 – Apr 16 |
| Peas | Sow outdoors: Mar 19 – Apr 2 |
| Spinach | Sow outdoors: Mar 19 – Apr 2 |
| Lettuce | Sow outdoors: Apr 2 – Apr 16 |
| Carrots | Sow outdoors: Apr 2 – Apr 16 |
| Potatoes | Plant outdoors: Apr 2 – Apr 16 |
| Beans | Sow outdoors: May 7 – May 14 |
| Sweet corn | Sow outdoors: May 7 – May 14 |
| Cucumbers | Sow outdoors: May 7 – May 14 |
| Squash & zucchini | Sow outdoors: May 7 – May 14 |
| Basil | Start seeds indoors: Mar 19 – Apr 2 Transplant outdoors: May 7 – May 14 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 21 (8 weeks before the average first fall frost on Oct 16).
Useful for zone 5b 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 16 | Apr 30 | May 16 |
| First 32°F frost in fall is before | Oct 29 | Oct 16 | Oct 1 |
How to read it: in spring there is a 10% chance of a frost after May 16, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 1. A hard freeze (28°F) usually ends around April 19.
Hardiness zone by ZIP code in Richfield
- 53076 zone 5b
Nearby cities
- Germantown zone 5b, last frost May 6
- Menomonee Falls zone 5b, last frost May 6
- Sussex zone 5b, last frost Apr 30
- Mequon zone 5b, last frost May 6
- West Bend zone 5b, last frost May 1
- Hartford zone 5a, last frost May 8
- Cedarburg zone 5b, last frost Apr 23
- Brookfield zone 5b, last frost Apr 30
Questions
What growing zone is Richfield, WI?
Richfield is in USDA Plant Hardiness Zone 5b (average extreme winter low -15°F to -10°F), according to the USDA 2023 map.
When is the last frost in Richfield?
The average last spring frost (32°F) in Richfield is April 30. There is still a 10% chance of frost until May 16.
When can I plant tomatoes in Richfield?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 7 – May 14. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Richfield 3 Ssw, WI (USC00477148), 5.2 km (3.2 mi) from the city center, elevation 300 m, based on 10 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.