When to plant sweet alyssum
Flower, hardy
Penn State lists sweet alyssum as a hardy annual and says hardy annual seed is best sown outdoors in fall, about 6 weeks before the first frost. Bedding plants can also go out in early spring; no separate spring week count was given.
The general rule
- Sow for fall
- 6 weeks before the first fall 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 | Sow for fall |
|---|---|---|
| San Jose, CA | Jan 23 | Oct 23 – Oct 23 |
| Tucson, AZ | Mar 2 | Oct 10 – Oct 10 |
| Portland, OR | Mar 21 | Sep 29 – Sep 29 |
| Baltimore, MD | Apr 4 | Sep 26 – Sep 26 |
| New York, NY | Apr 12 | Sep 25 – Sep 25 |
| Nashville, TN | Apr 16 | Sep 6 – Sep 6 |
| Louisville, KY | Apr 23 | Sep 9 – Sep 9 |
| Omaha, NE | May 6 | Aug 21 – Aug 21 |
| Colorado Springs, CO | May 15 | Aug 15 – Aug 15 |
| Miami, FL | Frost rare | Frost is rare: fall and winter. |