When to plant sunflowers
Plant sunflowers 1–3 weeks after the last spring frost. Wait until the soil is at least 55°F. That works out to zone 5b (mid May to late May), zone 7a (late April to early May) and zone 9a (early March to late March).
Sunflowers planting dates by zone
| Zone | Plant outdoors | sunflowers ready from |
|---|---|---|
| 4a | May 22 – Jun 5 | Aug 7 |
| 4b | May 20 – Jun 3 | Aug 5 |
| 5a | May 18 – Jun 1 | Aug 3 |
| 5b | May 12 – May 26 | Jul 28 |
| 6a | May 7 – May 21 | Jul 23 |
| 6b | May 1 – May 15 | Jul 17 |
| 7a | Apr 22 – May 6 | Jul 8 |
| 7b | Apr 13 – Apr 27 | Jun 29 |
| 8a | Apr 3 – Apr 17 | Jun 19 |
| 8b | Mar 23 – Apr 6 | Jun 8 |
| 9a | Mar 9 – Mar 23 | May 25 |
| 9b | Feb 11 – Feb 25 | Apr 29 |
How to plant sunflowers
| Plant as | seeds outdoors |
|---|---|
| Soil temperature | 55°F or warmer |
| Depth | 1 in |
| Spacing | 6–24 in |
| Light | Full sun |
| Time to bloom | 70–100 days |
Sunflowers grow best sown where they will bloom; they dislike transplanting.
Sow every 2–3 weeks until midsummer for continuous flowers.
Protect seedlings from birds and squirrels.
When to expect flowers from sunflowers
For seeds, cut heads when the back turns yellow-brown and petals fall; dry them upside down.
Exact dates for your town: planting calendar · frost dates by state.
More flowers to plant
Begonias · Coleus · Marigolds · Zinnias · Cosmos · Mums · Lantana · Hydrangeas