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When to Plant Cosmos in Louisiana

Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.

Louisiana spans USDA hardiness zones 8b, 9a, 9b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

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Find Your County

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

Cosmos Planting Calendar for Louisiana

Zone 8b ~276 day growing season · Full guide →

Last frost: February 25 · First frost: November 28 · 276 day season

Activity When Date Range
Start Indoors January 28 Jan 28 – Feb 11
Transplant Outdoors February 4 Feb 4 – Feb 18
Direct Sow February 4 Feb 4 – Feb 25
Bloom April 15 Apr 15 – Sep 16
Zone 9a ~303 day growing season · Full guide →

Last frost: February 10 · First frost: December 10 · 303 day season

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors January 13 Jan 13 – Jan 27
Direct Sow January 13 Jan 13 – Feb 3
Bloom March 24 Mar 24 – Sep 8
Zone 9b ~329 day growing season · Full guide →

Last frost: January 25 · First frost: December 20 · 329 day season

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors December 21 Dec 21 – Jan 4
Direct Sow December 21 Dec 21 – Jan 11
Bloom March 1 Mar 1 – Aug 30

Growing Tips for Louisiana

Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.

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Frequently Asked Questions

When should I plant Cosmos in Louisiana?

Planting dates for Cosmos in Louisiana depend on your USDA zone. Louisiana spans zones 8b, 9a, 9b. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Louisiana for planting?

Louisiana contains USDA hardiness zones 8b, 9a, 9b. 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.