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When to Plant Rosemary in Illinois

Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.

Illinois spans USDA hardiness zones 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 Rosemary planting dates based on your local frost dates.

Rosemary Planting Calendar for Illinois

Zone 7a ~221 day growing season · Full guide →

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

Activity When Date Range
Transplant Outdoors April 1 Apr 1 – Apr 15
Harvest June 24 Jun 24 – Nov 11

Growing Tips for Illinois

Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.

Frequently Asked Questions

When should I plant Rosemary in Illinois?

Planting dates for Rosemary in Illinois depend on your USDA zone. Illinois spans zones 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 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: April 2026.