When to plant mexican sunflower
Flower, tender
Sow indoors 6–8 weeks before the last spring frost, or direct-sow after that frost date. Wisconsin says it blooms from midsummer until frost and gets floppy in rich soil, so skip the extra fertilizer.
The general rule
- Start indoors
- 6–8 weeks before the last spring frost
- Sow outdoors
- at the last spring frost
- Days to maturity
- Varies by variety
What that means in different climates
The same rule applied to the safer frost dates of cities from cold to frost-free.
| City | Last frost · safer | Start indoors | Sow outdoors |
|---|---|---|---|
| San Jose, CA | Jan 23 | Nov 28 – Dec 12 | Jan 23 – Jan 23 |
| Tucson, AZ | Mar 2 | Jan 5 – Jan 19 | Mar 2 – Mar 2 |
| Portland, OR | Mar 21 | Jan 24 – Feb 7 | Mar 21 – Mar 21 |
| Baltimore, MD | Apr 4 | Feb 7 – Feb 21 | Apr 4 – Apr 4 |
| New York, NY | Apr 12 | Feb 15 – Mar 1 | Apr 12 – Apr 12 |
| Nashville, TN | Apr 16 | Feb 19 – Mar 5 | Apr 16 – Apr 16 |
| Louisville, KY | Apr 23 | Feb 26 – Mar 12 | Apr 23 – Apr 23 |
| Omaha, NE | May 6 | Mar 11 – Mar 25 | May 6 – May 6 |
| Colorado Springs, CO | May 15 | Mar 20 – Apr 3 | May 15 – May 15 |
| Miami, FL | Frost rare | Frost is rare: late winter to spring; late summer to fall. | |