When to Plant Onion in Arizona
Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.
Arizona spans USDA hardiness zones 10a, 5b, 6a, 7a, 7b, 8a, 8b, 9a, 9b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.
Find Your County
Click your county for exact Onion planting dates based on your local frost dates.
Hover over a county to see details. Click to view planting guide.
Onion Planting Calendar for Arizona
▸ Zone 10a ~364 day growing season · Full guide →
Last frost: January 1 · First frost: December 31 · 364 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 4 | Dec 4 – Dec 18 |
| Transplant Outdoors | January 1 | Jan 1 – Jan 15 |
| Direct Sow | December 11 | Dec 11 – Jan 1 |
| Fall Sowing | November 5 | Nov 5 – Nov 19 |
| Harvest | April 2 | Apr 2 – May 21 |
▸ Zone 5b ~178 day growing season · Full guide →
Last frost: April 18 · First frost: October 13 · 178 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 4 | Apr 4 – Apr 25 |
| Fall Sowing | August 4 | Aug 4 – Aug 18 |
| Harvest | July 18 | Jul 18 – Sep 5 |
▸ Zone 6a ~193 day growing season · Full guide →
Last frost: April 10 · First frost: October 20 · 193 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Direct Sow | March 27 | Mar 27 – Apr 17 |
| Fall Sowing | August 11 | Aug 11 – Aug 25 |
| Harvest | July 10 | Jul 10 – Aug 28 |
▸ Zone 7a ~221 day growing season · Full guide →
Last frost: March 25 · First frost: November 1 · 221 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 18 | Feb 18 – Mar 4 |
| Transplant Outdoors | March 25 | Mar 25 – Apr 8 |
| Direct Sow | March 11 | Mar 11 – Apr 1 |
| Fall Sowing | August 23 | Aug 23 – Sep 6 |
| Harvest | June 24 | Jun 24 – Aug 12 |
▸ Zone 7b ~235 day growing season · Full guide →
Last frost: March 18 · First frost: November 8 · 235 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 11 | Feb 11 – Feb 25 |
| Transplant Outdoors | March 18 | Mar 18 – Apr 1 |
| Direct Sow | March 4 | Mar 4 – Mar 25 |
| Fall Sowing | August 30 | Aug 30 – Sep 13 |
| Harvest | June 17 | Jun 17 – Aug 5 |
▸ Zone 8a ~255 day growing season · Full guide →
Last frost: March 8 · First frost: November 18 · 255 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 1 | Feb 1 – Feb 15 |
| Transplant Outdoors | March 8 | Mar 8 – Mar 22 |
| Direct Sow | February 22 | Feb 22 – Mar 15 |
| Fall Sowing | September 9 | Sep 9 – Sep 23 |
| Harvest | June 7 | Jun 7 – Jul 26 |
▸ Zone 8b ~276 day growing season · Full guide →
Last frost: February 25 · First frost: November 28 · 276 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 21 | Jan 21 – Feb 4 |
| Transplant Outdoors | February 25 | Feb 25 – Mar 11 |
| Direct Sow | February 11 | Feb 11 – Mar 4 |
| Fall Sowing | September 19 | Sep 19 – Oct 3 |
| Harvest | May 27 | May 27 – Jul 15 |
▸ Zone 9a ~303 day growing season · Full guide →
Last frost: February 10 · First frost: December 10 · 303 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 13 | Jan 13 – Jan 27 |
| Transplant Outdoors | February 10 | Feb 10 – Feb 24 |
| Direct Sow | January 20 | Jan 20 – Feb 10 |
| Fall Sowing | October 15 | Oct 15 – Oct 29 |
| Harvest | May 12 | May 12 – Jun 30 |
▸ Zone 9b ~329 day growing season · Full guide →
Last frost: January 25 · First frost: December 20 · 329 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 28 | Dec 28 – Jan 11 |
| Transplant Outdoors | January 25 | Jan 25 – Feb 8 |
| Direct Sow | January 4 | Jan 4 – Jan 25 |
| Fall Sowing | October 25 | Oct 25 – Nov 8 |
| Harvest | April 26 | Apr 26 – Jun 14 |
Growing Tips for Arizona
Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.
Onion in Other States
- Alabama
- Alaska
- Alberta
- Arkansas
- British Columbia
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Manitoba
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Brunswick
- New Hampshire
- New Jersey
- New Mexico
- New York
- Newfoundland and Labrador
- North Carolina
- North Dakota
- Northwest Territories
- Nova Scotia
- Nunavut
- Ohio
- Oklahoma
- Ontario
- Oregon
- Pennsylvania
- Prince Edward Island
- Quebec
- Rhode Island
- Saskatchewan
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
- Yukon
Frequently Asked Questions
When should I plant Onion in Arizona?
Planting dates for Onion in Arizona depend on your USDA zone. Arizona spans zones 10a, 5b, 6a, 7a, 7b, 8a, 8b, 9a, 9b. Check the planting calendar above for your specific zone's frost dates and planting windows.
What zone is Arizona for planting?
Arizona contains USDA hardiness zones 10a, 5b, 6a, 7a, 7b, 8a, 8b, 9a, 9b. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.