Cool-Season Vegetable

When to Plant Peas in Illinois

One of the earliest crops you can plant. Kids love picking and eating them right off the vine.

The Short Answer

Peas are cold-tolerant and do well in Illinois's humid climate. You can direct sow 6 weeks before your last frost — that's as early as Apr 25 - May 10 in Northern Illinois (Chicago). Illinois gardeners can also plant a fall crop. Rich prairie soils — some of the most fertile in the country. Heavy clay in many areas. Well-suited...

Illinois Frost Dates

Your planting dates depend on which part of Illinois you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Illinois (Chicago) 5a, 5b Apr 25 - May 10 Oct 1 - Oct 15
Central Illinois 5b, 6a Apr 15 - May 1 Oct 5 - Oct 20
Southern Illinois 6b, 7a Apr 1 - Apr 15 Oct 15 - Nov 1

Peas Planting Schedule for Illinois

Northern Illinois (Chicago) (Zones 5a, 5b)

Average last frost: Apr 25 - May 10 · Average first frost: Oct 1 - Oct 15

Direct Sow
6 wks before frost
Fall Planting
8 wks before first frost

Central Illinois (Zones 5b, 6a)

Average last frost: Apr 15 - May 1 · Average first frost: Oct 5 - Oct 20

Direct Sow
6 wks before frost
Fall Planting
8 wks before first frost

Southern Illinois (Zones 6b, 7a)

Average last frost: Apr 1 - Apr 15 · Average first frost: Oct 15 - Nov 1

Direct Sow
6 wks before frost
Fall Planting
8 wks before first frost

Growing Peas in Illinois

Peas in Illinois's Climate

Peas are your first spring crop — direct sow 4-6 weeks before last frost. Production continues until temperatures consistently exceed 80°F, usually by late June. Fall peas from an August sowing produce well into October. Provide trellising for climbing varieties.

Soil Considerations for Illinois

Rich prairie soils — some of the most fertile in the country. Heavy clay in many areas. Well-suited for most vegetables.

Illinois Climate & Growing Season

Continental climate with four seasons. Hot, humid summers. Cold winters. Good growing season length in central and southern regions. Peas can handle frost well, which is an advantage in Illinois's climate. You can push planting dates earlier in spring and extend into fall.

Growing season length varies across Illinois: Northern Illinois (Chicago) (5a, 5b) has a last frost around Apr 25 - May 10, while Southern Illinois (6b, 7a) sees frost end around Apr 1 - Apr 15. This difference matters for peas — but peas handle frost well, so the timing difference is less critical.

Growing Tips

Direct sow as early as the soil can be worked. Inoculate with rhizobium for bigger harvests. Provide a trellis for climbing varieties.

Companion Planting

Plant peas alongside these companions for better growth:

Carrots Radishes Corn Cucumbers

Keep peas away from:

Onions Garlic

The Bottom Line

Peas can be grown successfully across Illinois, but your exact planting dates depend on which region you're in. Northern Illinois (Chicago) gardeners should plan around a Apr 25 - May 10 last frost, while those in Southern Illinois can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Peas Growing Guide National planting guide with all states Illinois Planting Calendar All plants for Illinois Peas in Alabama Alabama planting dates Peas in Alaska Alaska planting dates Peas in Arizona Arizona planting dates Peas in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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