Brookfield, IL planting zone & frost dates
Brookfield is in USDA hardiness zone 6a. The last spring frost usually comes around April 11 and the first fall frost around October 31, for a growing season of about 201 days.
Planting calendar for Brookfield
Dates are counted from the average last spring frost (April 11) 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 14 – Feb 28 Transplant outdoors: Apr 18 – Apr 25 |
| Peppers | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Apr 25 – May 2 |
| Eggplant | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Apr 25 – May 2 |
| Broccoli | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Mar 14 – Mar 28 |
| Cabbage | Start seeds indoors: Jan 31 – Feb 14 Transplant outdoors: Mar 14 – Mar 28 |
| Onions (sets) | Plant outdoors: Mar 14 – Mar 28 |
| Peas | Sow outdoors: Feb 28 – Mar 14 |
| Spinach | Sow outdoors: Feb 28 – Mar 14 |
| Lettuce | Sow outdoors: Mar 14 – Mar 28 |
| Carrots | Sow outdoors: Mar 14 – Mar 28 |
| Potatoes | Plant outdoors: Mar 14 – Mar 28 |
| Beans | Sow outdoors: Apr 18 – Apr 25 |
| Sweet corn | Sow outdoors: Apr 18 – Apr 25 |
| Cucumbers | Sow outdoors: Apr 18 – Apr 25 |
| Squash & zucchini | Sow outdoors: Apr 18 – Apr 25 |
| Basil | Start seeds indoors: Feb 28 – Mar 14 Transplant outdoors: Apr 18 – Apr 25 |
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 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 | Mar 30 | Apr 11 | Apr 27 |
| First 32°F frost in fall is before | Nov 14 | Oct 31 | Oct 20 |
How to read it: in spring there is a 10% chance of a frost after April 27, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 20. A hard freeze (28°F) usually ends around April 1.
Hardiness zone by ZIP code in Brookfield
- 60513 zone 6a
Nearby cities
- La Grange Park zone 6a, last frost Apr 11
- La Grange zone 6a, last frost Apr 11
- Lyons zone 6a, last frost Apr 11
- Westchester zone 6a, last frost Apr 11
- Western Springs zone 6a, last frost Apr 19
- Summit zone 6a, last frost Apr 11
- Maywood zone 6a, last frost Apr 11
- Berwyn zone 6a, last frost Apr 11
Questions
What growing zone is Brookfield, IL?
Brookfield 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 Brookfield?
The average last spring frost (32°F) in Brookfield is April 11. There is still a 10% chance of frost until April 27.
When can I plant tomatoes in Brookfield?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 18 – Apr 25. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Chicago Midway Ap, IL (USW00014819), 9.3 km (5.8 mi) from the city center, elevation 186 m, based on 23 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.