When to plant basil in Arizona
Arizona’s average last spring frost is March 15, and the first fall frost typically arrives around November 15 — about 245 frost-free days (USDA zones 4b, 5b, 6b, 7b, 8b, 9b, 10b). Basil needs 30–60 days to mature, which fits comfortably within Arizona's growing season.
Arizona covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant basil in Arizona: the short answer
For a spring planting, plant out Mar 22 – Apr 8, with seeds started indoors Feb 1 – Feb 15. Wait until the soil is at least 65°F and frost is over.
Succession sow again in Arizona: Apr 19 · May 10 · May 31 · Jun 21 · Jul 12 · Aug 2 · Aug 23 · Sep 13
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow basil in Arizona, step by step
- Start seeds indoors (Feb 1 – Feb 15). Sow seeds ⅛ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 80°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 10 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (Mar 22 – Apr 8). Space plants about 10 inches apart in rows 12 inches apart. It is killed by frost, so nothing goes outside until the danger has passed.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: aphids, Japanese beetle, slugs. Diseases and disorders: basil downy mildew, fusarium wilt, damping off.
- Harvest (from about Apr 28 – May 28). Basil takes 30-60 days to reach harvest. Cold soil stalls it - wait for warm nights. Pinch above a leaf pair every couple of weeks and remove flower buds to keep leaves coming. Downy mildew-resistant varieties are worth seeking out.
Figures come from our crop data; dates use Arizona’s average frost dates. More in the full basil growing guide.
Basil planting dates by USDA zone in Arizona
Arizona spans USDA zones 4b, 5b, 6b, 7b, 8b, 9b, 10b. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the basil dates shift with them.
| Zone | Last frost | First frost | Season | Start indoors | Plant basil |
|---|---|---|---|---|---|
| Zone 4 | May 10 | Sep 25 | 135 days | Mar 29 – Apr 12 | May 17 – Jun 3 |
| Zone 5 | Apr 30 | Oct 5 | 160 days | Mar 19 – Apr 2 | May 7 – May 24 |
| Zone 6 | Apr 15 | Oct 15 | 185 days | Mar 4 – Mar 18 | Apr 22 – May 9 |
| Zone 7 | Apr 5 | Oct 25 | 200 days | Feb 22 – Mar 8 | Apr 12 – Apr 29 |
| Zone 8 | Mar 20 | Nov 5 | 230 days | Feb 6 – Feb 20 | Mar 27 – Apr 13 |
| Zone 9 | Feb 20 | Nov 30 | 280 days | Jan 9 – Jan 23 | Feb 27 – Mar 16 |
| Zone 10 | Jan 30 | Dec 15 | 330 days | Dec 19 – Jan 2 | Feb 6 – Feb 23 |
When to plant basil in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Arizona (this page) | March 15 | Mar 22 – Apr 8 |
| New Mexico | April 20 | Apr 27 – May 14 |
Questions gardeners in Arizona ask
When is the best time to plant basil in Arizona?
Plant basil transplants outdoors in Arizona between March 22 and April 8. That timing is set by Arizona's average last spring frost of March 15; Arizona spans several climates, so cooler and higher parts of the state run later.
When should I start basil seeds indoors in Arizona?
Start seeds indoors between February 1 and February 15, about 5 weeks before the last frost, so the seedlings are ready to plant out from March 22.
What is the latest I can plant basil in Arizona?
About October 16. Basil needs at least 30 days to mature, and frost around November 15 ends the season, so later plantings risk being cut short.
When will basil planted in Arizona be ready to harvest?
Planted on time, basil is usually ready from about April 28 to May 28, 30-60 days after planting.
When is the last frost in Arizona?
On average around March 15, with the first fall frost around November 15 - about 245 frost-free days. Your town may differ by two weeks or more.