Lombard, IL planting zone & frost dates
Lombard is in USDA hardiness zone 6a. The last spring frost usually comes around April 28 and the first fall frost around October 16, for a growing season of about 169 days.
Planting calendar for Lombard
Dates are counted from the average last spring frost (April 28) 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 3 – Mar 17 Transplant outdoors: May 5 – May 12 |
| Peppers | Start seeds indoors: Feb 17 – Mar 3 Transplant outdoors: May 12 – May 19 |
| Eggplant | Start seeds indoors: Feb 17 – Mar 3 Transplant outdoors: May 12 – May 19 |
| Broccoli | Start seeds indoors: Feb 17 – Mar 3 Transplant outdoors: Mar 31 – Apr 14 |
| Cabbage | Start seeds indoors: Feb 17 – Mar 3 Transplant outdoors: Mar 31 – Apr 14 |
| Onions (sets) | Plant outdoors: Mar 31 – Apr 14 |
| Peas | Sow outdoors: Mar 17 – Mar 31 |
| Spinach | Sow outdoors: Mar 17 – Mar 31 |
| Lettuce | Sow outdoors: Mar 31 – Apr 14 |
| Carrots | Sow outdoors: Mar 31 – Apr 14 |
| Potatoes | Plant outdoors: Mar 31 – Apr 14 |
| Beans | Sow outdoors: May 5 – May 12 |
| Sweet corn | Sow outdoors: May 5 – May 12 |
| Cucumbers | Sow outdoors: May 5 – May 12 |
| Squash & zucchini | Sow outdoors: May 5 – May 12 |
| Basil | Start seeds indoors: Mar 17 – Mar 31 Transplant outdoors: May 5 – May 12 |
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 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 28 | May 14 |
| 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 14, 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 16.
Hardiness zone by ZIP code in Lombard
- 60148 zone 6a
Nearby cities
- Villa Park zone 6a, last frost Apr 28
- Addison zone 6a, last frost Apr 16
- Glen Ellyn zone 6a, last frost Apr 28
- Glendale Heights zone 5b, last frost Apr 28
- Elmhurst zone 6a, last frost Apr 16
- Downers Grove zone 6a, last frost Apr 28
- Wood Dale zone 6a, last frost Apr 16
- Westmont zone 6a, last frost Apr 28
Questions
What growing zone is Lombard, IL?
Lombard 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 Lombard?
The average last spring frost (32°F) in Lombard is April 28. There is still a 10% chance of frost until May 14.
When can I plant tomatoes in Lombard?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 5 – May 12. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Lisle-Morton Arboretum, IL (USC00115097), 9.2 km (5.7 mi) from the city center, elevation 207 m, based on 13 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.