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When to Plant Marigolds in Illinois

Marigolds (Tagetes patula) are warm-season annuals beloved for their cheerful orange, yellow, and red blooms — and for their well-documented ability to repel pest nematodes in vegetable beds. Easy from seed, drought-tolerant once established, and bloom from early summer until the first hard frost.

Illinois spans USDA hardiness zones 5a, 5b, 6a, 6b, 7a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Marigolds planting dates based on your local frost dates.

Marigolds Planting Calendar for Illinois

Zone 5a ~166 day growing season · Full guide →

Last frost: April 25 · First frost: October 8 · 166 day season

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors May 2 May 2 – May 16
Direct Sow May 2 May 2 – May 23
Bloom June 27 Jun 27 – Sep 19
Zone 5b ~178 day growing season · Full guide →

Last frost: April 18 · First frost: October 13 · 178 day season

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 25 Apr 25 – May 16
Bloom June 20 Jun 20 – Sep 19
Zone 6a ~193 day growing season · Full guide →

Last frost: April 10 · First frost: October 20 · 193 day season

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 17 Apr 17 – May 1
Direct Sow April 17 Apr 17 – May 8
Bloom June 12 Jun 12 – Sep 11
Zone 6b ~205 day growing season · Full guide →

Last frost: April 3 · First frost: October 25 · 205 day season

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow April 3 Apr 3 – Apr 24
Bloom May 29 May 29 – Sep 4
Zone 7a ~221 day growing season · Full guide →

Last frost: March 25 · First frost: November 1 · 221 day season

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow March 25 Mar 25 – Apr 15
Bloom May 20 May 20 – Aug 26

Growing Tips for Illinois

Direct-sow after last frost or start indoors 4-6 weeks earlier. Deadhead spent blooms to keep new flowers coming. French marigolds (T. patula) are the most reliable nematode repellents — plant a band around vegetable beds. Tolerate poor soil but bloom best with monthly compost.

Frequently Asked Questions

When should I plant Marigolds in Illinois?

Planting dates for Marigolds in Illinois depend on your USDA zone. Illinois spans zones 5a, 5b, 6a, 6b, 7a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Illinois for planting?

Illinois contains USDA hardiness zones 5a, 5b, 6a, 6b, 7a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: June 2026.