When to Plant Onions (sets or transplants)
Onions are cold-hardy. Plant sets or transplants early so they grow leaves before long summer days trigger bulbing.
- Start indoors: 10–12 weeks before the last frost.
- Plant outside: 2–4 weeks before the last frost.
Onions (sets or transplants) planting dates in major cities
| City | Start indoors | Plant outside |
|---|---|---|
| Mesa, AZ | Nov 9 – Nov 23 | Jan 4 – Jan 18 |
| Phoenix, AZ | Oct 16 – Oct 30 | Dec 11 – Dec 25 |
| Tucson, AZ | Nov 13 – Nov 27 | Jan 8 – Jan 22 |
| Anaheim, CA | Oct 13 – Oct 27 | Dec 8 – Dec 22 |
| Bakersfield, CA | Nov 8 – Nov 22 | Jan 3 – Jan 17 |
| Fresno, CA | Oct 22 – Nov 5 | Dec 17 – Dec 31 |
| Irvine, CA | Oct 13 – Oct 27 | Dec 8 – Dec 22 |
| Long Beach, CA | Oct 17 – Oct 31 | Dec 12 – Dec 26 |
| Los Angeles, CA | Oct 10 – Oct 24 | Dec 5 – Dec 19 |
| Oakland, CA | Oct 15 – Oct 29 | Dec 10 – Dec 24 |
| Riverside, CA | Oct 17 – Oct 31 | Dec 12 – Dec 26 |
| Sacramento, CA | Oct 20 – Nov 3 | Dec 15 – Dec 29 |
| San Diego, CA | Oct 14 – Oct 28 | Dec 9 – Dec 23 |
| San Francisco, CA | Oct 7 – Oct 21 | Dec 2 – Dec 16 |
| San Jose, CA | Oct 10 – Oct 24 | Dec 5 – Dec 19 |
| Stockton, CA | Nov 13 – Nov 27 | Jan 8 – Jan 22 |
| Aurora, CO | Feb 12 – Feb 26 | Apr 9 – Apr 23 |
| Colorado Springs, CO | Feb 8 – Feb 22 | Apr 5 – Apr 19 |
| Denver, CO | Feb 9 – Feb 23 | Apr 6 – Apr 20 |
| Washington, DC | Jan 4 – Jan 18 | Mar 1 – Mar 15 |
| Jacksonville, FL | Nov 9 – Nov 23 | Jan 4 – Jan 18 |
| Orlando, FL | Nov 2 – Nov 16 | Dec 28 – Jan 11 |
| Tampa, FL | Oct 28 – Nov 11 | Dec 23 – Jan 6 |
| Atlanta, GA | Dec 30 – Jan 13 | Feb 24 – Mar 10 |
| Chicago, IL | Jan 16 – Jan 30 | Mar 13 – Mar 27 |
| Indianapolis city, IN | Jan 26 – Feb 9 | Mar 23 – Apr 6 |
| Wichita, KS | Jan 17 – Jan 31 | Mar 14 – Mar 28 |
| Lexington-Fayette, KY | Jan 19 – Feb 2 | Mar 16 – Mar 30 |
| Louisville/Jefferson County metro government, KY | Jan 12 – Jan 26 | Mar 9 – Mar 23 |
| New Orleans, LA | Oct 30 – Nov 13 | Dec 25 – Jan 8 |
| Boston, MA | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Baltimore, MD | Dec 30 – Jan 13 | Feb 24 – Mar 10 |
| Detroit, MI | Feb 2 – Feb 16 | Mar 30 – Apr 13 |
| Minneapolis, MN | Jan 29 – Feb 12 | Mar 26 – Apr 9 |
| Kansas City, MO | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Charlotte, NC | Jan 5 – Jan 19 | Mar 2 – Mar 16 |
| Raleigh, NC | Jan 3 – Jan 17 | Feb 28 – Mar 14 |
| Omaha, NE | Jan 22 – Feb 5 | Mar 19 – Apr 2 |
| Albuquerque, NM | Jan 29 – Feb 12 | Mar 26 – Apr 9 |
| Henderson, NV | Oct 28 – Nov 11 | Dec 23 – Jan 6 |
| Las Vegas, NV | Nov 1 – Nov 15 | Dec 27 – Jan 10 |
| New York, NY | Jan 7 – Jan 21 | Mar 4 – Mar 18 |
| Cleveland, OH | Jan 14 – Jan 28 | Mar 11 – Mar 25 |
| Columbus, OH | Jan 26 – Feb 9 | Mar 23 – Apr 6 |
| Oklahoma City, OK | Jan 10 – Jan 24 | Mar 7 – Mar 21 |
| Tulsa, OK | Jan 6 – Jan 20 | Mar 3 – Mar 17 |
| Portland, OR | Dec 3 – Dec 17 | Jan 28 – Feb 11 |
| Philadelphia, PA | Jan 5 – Jan 19 | Mar 2 – Mar 16 |
| Memphis, TN | Dec 22 – Jan 5 | Feb 16 – Mar 2 |
| Nashville-Davidson, TN | Jan 7 – Jan 21 | Mar 4 – Mar 18 |
| Arlington, TX | Dec 15 – Dec 29 | Feb 9 – Feb 23 |
| Austin, TX | Nov 28 – Dec 12 | Jan 23 – Feb 6 |
| Dallas, TX | Dec 8 – Dec 22 | Feb 2 – Feb 16 |
| El Paso, TX | Dec 8 – Dec 22 | Feb 2 – Feb 16 |
| Fort Worth, TX | Dec 11 – Dec 25 | Feb 5 – Feb 19 |
| Houston, TX | Nov 10 – Nov 24 | Jan 5 – Jan 19 |
| San Antonio, TX | Dec 3 – Dec 17 | Jan 28 – Feb 11 |
| Virginia Beach, VA | Jan 4 – Jan 18 | Mar 1 – Mar 15 |
| Seattle, WA | Dec 14 – Dec 28 | Feb 8 – Feb 22 |
| Milwaukee, WI | Feb 1 – Feb 15 | Mar 29 – Apr 12 |
Calculated from each city's average (50%) frost dates. In a cold spring, lean toward the later end of each window.