Galesburg, IL planting zone & frost dates
Galesburg is in USDA hardiness zone 5b. The last spring frost usually comes around April 20 and the first fall frost around October 19, for a growing season of about 180 days.
Planting calendar for Galesburg
Dates are counted from the average last spring frost (April 20) 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 23 – Mar 9 Transplant outdoors: Apr 27 – May 4 |
| Peppers | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: May 4 – May 11 |
| Eggplant | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: May 4 – May 11 |
| Broccoli | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: Mar 23 – Apr 6 |
| Cabbage | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: Mar 23 – Apr 6 |
| Onions (sets) | Plant outdoors: Mar 23 – Apr 6 |
| Peas | Sow outdoors: Mar 9 – Mar 23 |
| Spinach | Sow outdoors: Mar 9 – Mar 23 |
| Lettuce | Sow outdoors: Mar 23 – Apr 6 |
| Carrots | Sow outdoors: Mar 23 – Apr 6 |
| Potatoes | Plant outdoors: Mar 23 – Apr 6 |
| Beans | Sow outdoors: Apr 27 – May 4 |
| Sweet corn | Sow outdoors: Apr 27 – May 4 |
| Cucumbers | Sow outdoors: Apr 27 – May 4 |
| Squash & zucchini | Sow outdoors: Apr 27 – May 4 |
| Basil | Start seeds indoors: Mar 9 – Mar 23 Transplant outdoors: Apr 27 – May 4 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 24 (8 weeks before the average first fall frost on Oct 19).
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 6 | Apr 20 | May 5 |
| First 32°F frost in fall is before | Oct 30 | Oct 19 | Oct 4 |
How to read it: in spring there is a 10% chance of a frost after May 5, 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 10.
Hardiness zone by ZIP code in Galesburg
- 61401 zone 5b
- 61402 zone 5b
Nearby cities
- Canton zone 6a, last frost Apr 17
- Kewanee zone 5b, last frost Apr 24
- East Moline zone 5b, last frost Apr 24
- Macomb zone 6a, last frost Apr 17
- Moline zone 5b, last frost Apr 19
- Rock Island zone 5b, last frost Apr 19
- North Peoria zone 6a, last frost Apr 16
- Peoria zone 6a, last frost Apr 16
Questions
What growing zone is Galesburg, IL?
Galesburg 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 Galesburg?
The average last spring frost (32°F) in Galesburg is April 20. There is still a 10% chance of frost until May 5.
When can I plant tomatoes in Galesburg?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 27 – May 4. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Galesburg, IL (USC00113320), 1.2 km (0.7 mi) from the city center, elevation 232 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.