When to Plant Cosmos in Vermont
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.
Vermont spans USDA hardiness zones 4b, 5a, 5b (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 Vermont
▸ Zone 4b ~155 day growing season · Full guide →
Last frost: May 1 · First frost: October 3 · 155 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 8 | May 8 – May 22 |
| Direct Sow | May 8 | May 8 – May 29 |
| Bloom | July 17 | Jul 17 – Oct 9 |
▸ 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 28 | Mar 28 – Apr 11 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | May 2 | May 2 – May 23 |
| Bloom | July 11 | Jul 11 – Oct 3 |
▸ 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 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 18 | Apr 18 – May 9 |
| Bloom | June 27 | Jun 27 – Sep 26 |
Growing Tips for Vermont
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 Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Cosmos in Vermont?
Planting dates for Cosmos in Vermont depend on your USDA zone. Vermont spans zones 4b, 5a, 5b. Check the planting calendar above for your specific zone's frost dates and planting windows.
What zone is Vermont for planting?
Vermont contains USDA hardiness zones 4b, 5a, 5b. 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.