When to Plant Cosmos in Unknown
Direct Sow Outdoors
Tuesday, February 10, 2026
State
Unknown
USDA Zones
5a, 7a, 7b, 8b, 9a, 9b
Avg Last Frost
Tuesday, February 10, 2026
Cities Covered
13
Unknown Planting Schedule by Zone
Unknown spans 6 zones — find yours below for the most accurate dates.
| Zone | Last Frost | Direct Sow |
|---|---|---|
| 5a | Sunday, May 10, 2026 | Sunday, May 10, 2026 |
| 7a | Friday, April 10, 2026 | Friday, April 10, 2026 |
| 7b | Sunday, April 5, 2026 | Sunday, April 5, 2026 |
| 8b | Sunday, March 15, 2026 | Sunday, March 15, 2026 |
| 9a | Friday, February 20, 2026 | Friday, February 20, 2026 |
| 9b | Tuesday, February 10, 2026 | Tuesday, February 10, 2026 |
Dates based on average last frost. Check your local forecast before planting.
🌿 About Cosmos
🤝 Companion Plants for Cosmos
Good Companions
Growing Cosmos in Unknown: Complete Guide
Cosmos (Cosmos bipinnatus) is a crop that grows best when sown directly in the garden. In Unknown, the right time to direct sow is around Tuesday, February 10, 2026, once soil temperatures are consistently warm enough for germination.
Because Unknown stretches across 6 USDA hardiness zones (5a, 7a, 7b, 8b, 9a, 9b), planting windows can shift by as much as six to eight weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.
With 60 days to maturity, Cosmos fits comfortably within Unknown's growing season in most zones. In the warmest parts of the state, a second planting later in the season may be possible.
Cosmos requires full sun (6-8 hours) and low-moderate moisture. Most of Unknown receives adequate sunlight during the growing season, though gardeners in humid eastern regions should watch for fungal issues and ensure good air circulation.
For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Unknown.
Frequently Asked Questions
When should I plant Cosmos in Unknown?
In Unknown, direct sow Cosmos outdoors around Tuesday, February 10, 2026. Unknown spans zones 5a–9b, so gardeners in warmer zones can plant earlier.
What is the last frost date in Unknown?
Unknown spans 6 USDA zones (5a, 7a, 7b, 8b, 9a, 9b), so last frost dates vary by region. ZIP 50099 (5a) sees frost until around Sunday, May 10, 2026, while ZIP 32143, ZIP 85117, ZIP 85127 (9b) is frost-free much earlier.
How long does Cosmos take to grow in Unknown?
Cosmos takes about 60 days from transplant (or direct sow) to harvest. In Unknown's longer-season zones, a second planting in late summer may be possible.
What USDA zones does Unknown cover for Cosmos?
Unknown includes zones 5a, 7a, 7b, 8b, 9a, 9b. Cosmos grows well across all of these zones with adjusted timing — use the zone table above to find the right dates for your part of the state.
Find Precise Dates for Your City
Select a city for exact planting dates based on local frost records.