Cosmos: The Wildflower That Keeps Blooming
Cosmos are tall, airy wildflowers that bloom from summer to frost. They thrive in poor soil — too much fertilizer means no flowers.
Cosmos are one of the easiest flowers to grow. They self-seed and come back every year in mild climates.
Quick Facts
| Attribute | Value |
|---|---|
| Days to sprout | 7-10 |
| Days to harvest | 60-75 |
| Sun | 6-8 hours |
| Spacing | 12-18 inches |
| Height | 3-5 feet |
| Colors | Pink, white, red, orange, yellow |
Why Grow It
- Long bloom season. Summer to first frost.
- Self-seeds. Comes back every year.
- Poor soil tolerant. Too much fertilizer = no flowers.
- Cut flower. 5-7 day vase life.
How It Fails
Failure 1: Leggy. Too much fertilizer or not enough sun. Failure 2: Few flowers. Too much nitrogen. Failure 3: Powdery mildew. Late season. Airflow helps.
Comparison
| Variety | Height | Days | Colors |
|---|---|---|---|
| Sensation | 3-5 ft | 60-75 | Mixed |
| Sonata | 2-3 ft | 60-75 | White |
| Cosmic | 1-2 ft | 55-65 | Mixed, dwarf |
| Bright Lights | 3-4 ft | 60-75 | Orange, yellow |
Common Questions
Why are my cosmos leggy? Too much fertilizer, or not enough sun.
Do they self-seed? Yes. Aggressively in mild climates.
When do I cut them? When flowers are open but before they fade.
Can I grow them in containers? Yes. Dwarf varieties work.
Do they attract bees? Yes. Bees and butterflies love cosmos.
Do they need staking? Tall varieties may need support in wind.