Perennial Flower

When to Plant Daylilies in Illinois

Nearly indestructible perennials with stunning trumpet-shaped blooms. Each flower lasts just one day, but the show goes on for weeks.

The Short Answer

In Illinois, plant daylilies based on your regional frost dates. Northern Illinois (Chicago) has a last frost around Apr 25 - May 10, while Southern Illinois sees frost end around Apr 1 - Apr 15. Continental climate with four seasons. Hot, humid summers. Cold winters. Good growing season length in central and...

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

Daylilies Planting Schedule for Illinois

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

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

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0 wks after frost

Central Illinois (Zones 5b, 6a)

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

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0 wks after frost

Southern Illinois (Zones 6b, 7a)

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

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0 wks after frost

Growing Daylilies in Illinois

Daylilies in Illinois's Climate

Daylilies thrive in your four-season climate. Plant from spring through early fall. The full range of varieties works — dormant, semi-evergreen, and evergreen. Minimal maintenance required. Divide every 3-4 years to maintain vigor.

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. Daylilies 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 daylilies — adjust your planting dates to match your specific region.

Growing Tips

Plant bare-root or divisions in spring or fall. Divide clumps every 3-4 years to maintain vigor. Deadhead to keep gardens tidy.

Companion Planting

Plant daylilies alongside these companions for better growth:

Coneflowers Black Eyed Susans

The Bottom Line

Daylilies 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

Daylilies Growing Guide National planting guide with all states Illinois Planting Calendar All plants for Illinois Daylilies in Alabama Alabama planting dates Daylilies in Alaska Alaska planting dates Daylilies in Arizona Arizona planting dates Daylilies 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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