When to Plant Green Beans in Illinois: Spring and Fall Dates by Region

University of Illinois Extension’s own green beans dates for Illinois, row by row and never averaged, beside NOAA frost dates for Chicago O'Hare International Airport, Peoria Greater Peoria Airport, and Springfield Capital Airport.

By Paul Gunder · How we check our sources

Updated November 11, 2026

Figures checked against their sources on November 11, 2026; next check May 8, 2027.

University of Illinois Extension gives green beans their own row under the heading “Bush Beans from Seed”, with dates for 3 regions. Across the rows, the first date to appear is April 26 (Southern Illinois) and the last is May 24 (Northern Illinois), 28 days apart.

Illinois’s dates, row by row

The page adds this line for the row: “Sow 2-4 inches apart and 1 inch deep.”

Green bean planting dates in Illinois, as printed by University of Illinois Extension (one row per region, none averaged)
Region	First planting	Second planting
Northern Illinois	May 24 to June 30	July 30 to Aug. 14
Central Illinois	May 10 to June 15	July 15 to 30
Southern Illinois	April 26 to June 1	July 1 to July 15

Reading the University of Illinois Extension table

Illinois Extension splits the state into northern, central and southern Illinois and prints one planting range for each. The page gives the median last 32-degree freeze as April 8-29 in northern Illinois, April 8-15 in central Illinois and April 1-8 in southern Illinois, and adds that last freezes have occurred both before and after those ranges.

Do green beans get an indoor start?

Indoor starts are not part of the usual routine here: in UNH’s list, green beans are sown where they will grow.

UNH lists beans as a seed crop sown after the last frost, with no indoor start, so the saved sources give no seed-starting weeks for beans at all.

UNH’s own timing for green beans is after the last frost, so Illinois’s printed window and UNH’s rule of thumb can be set side by side.

Indoor start for green beans: what each saved source says (one row per source, none averaged)
Source	What it says
University of New Hampshire	Not started indoors; sow seed after the last frost

Frost dates for Illinois cities

These are station dates from weather records, not county averages. Pick the station closest to your garden and elevation, and open its link for the full set of probabilities.

Regions in the last column come from the source’s wording, never from our reading of a map.

NOAA 1991-2020 normals for Illinois stations: 50% last spring and first fall 32°F dates
Station	Last spring 32°F	First fall 32°F	Region in Illinois’s calendar
Chicago O'Hare International Airport, Illinois	April 16	October 28	Northern Illinois
Peoria Greater Peoria Airport, Illinois	April 16	October 23	Not stated by the source
Springfield Capital Airport, Illinois	April 14	October 20	Not stated by the source
Carbondale Southern Il Airport, Illinois	April 9	October 22	Not stated by the source
Rockford Greater Rockford Airport, Illinois	April 24	October 17	Not stated by the source

Worked example

NOAA’s normals for Chicago O'Hare International Airport, Illinois give April 16 as the even-odds date of the last spring 32°F night, and October 28 as the even-odds first fall one.

Set the frost date against Northern Illinois: the window opens May 24, 38 days after it, and shuts June 30, 75 days after it.

On the fall side, Northern Illinois’ last planting date of August 14 leaves 75 days before the October 28 median first freeze.

Do the same subtraction for your own town: choose its nearest station in the frost dates tool, take the 50% dates, and compare them with the row for your part of Illinois.

Before you rely on these dates

The page tells readers to always confirm dates with the seed packet or plant tag.

Soil that is cold or soaked can hold a crop back even inside the printed window, so check the ground as well as the calendar.

Sources (3)