When to Plant Cosmos in South Carolina
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.
South Carolina spans USDA hardiness zones 8a, 8b, 9a (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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Click your county for exact Cosmos planting dates based on your local frost dates.
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Cosmos Planting Calendar for South Carolina
▸ Zone 8a ~255 day growing season · Full guide →
Last frost: March 8 · First frost: November 18 · 255 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 8 | Feb 8 – Feb 22 |
| Transplant Outdoors | February 22 | Feb 22 – Mar 8 |
| Direct Sow | February 22 | Feb 22 – Mar 15 |
| Bloom | May 3 | May 3 – Sep 20 |
▸ 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 |
Growing Tips for South Carolina
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.
Cosmos in Other States
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Cosmos in South Carolina?
Planting dates for Cosmos in South Carolina depend on your USDA zone. South Carolina spans zones 8a, 8b, 9a. Check the planting calendar above for your specific zone's frost dates and planting windows.
What zone is South Carolina for planting?
South Carolina contains USDA hardiness zones 8a, 8b, 9a. 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.