When to plant swiss chard 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). Swiss Chard needs 50–60 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 swiss chard in Arizona: the short answer
For a spring planting, plant out Feb 22 – Mar 11, with seeds started indoors Feb 8 – Feb 22. Seeds germinate in soil from 40 to 85°F.
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 swiss chard in Arizona, step by step
- Start seeds indoors (Feb 8 – Feb 22). Sow seeds 0.75 inch deep in seed-starting mix under bright light. They take 5-14 days to sprout, fastest in soil around 70°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough and loose soil at least 12 inches deep, with a pH between 6.0 and 7.5. Dig in compost before planting.
- Plant out (Feb 22 – Mar 11). Space plants about 9 inches apart in rows 18 inches apart. It tolerates a light frost but not a hard freeze. As a cool-season crop it does best before summer heat arrives in Arizona.
- 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: leaf miner, aphids, flea beetle. Diseases and disorders: cercospora leaf spot, downy mildew.
- Harvest (from about Apr 20 – Apr 30). Swiss Chard takes 50-60 days to reach harvest. One of the most heat-tolerant leafy greens - a single spring sowing usually carries through summer into fall if kept picked.
Figures come from our crop data; dates use Arizona’s average frost dates. More in the full swiss chard growing guide.
Swiss Chard 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 swiss chard dates shift with them.
| Zone | Last frost | First frost | Season | Start indoors | Plant swiss chard |
|---|---|---|---|---|---|
| Zone 4 | May 10 | Sep 25 | 135 days | Apr 5 – Apr 19 | Apr 19 – May 6 |
| Zone 5 | Apr 30 | Oct 5 | 160 days | Mar 26 – Apr 9 | Apr 9 – Apr 26 |
| Zone 6 | Apr 15 | Oct 15 | 185 days | Mar 11 – Mar 25 | Mar 25 – Apr 11 |
| Zone 7 | Apr 5 | Oct 25 | 200 days | Mar 1 – Mar 15 | Mar 15 – Apr 1 |
| Zone 8 | Mar 20 | Nov 5 | 230 days | Feb 13 – Feb 27 | Feb 27 – Mar 16 |
| Zone 9 | Feb 20 | Nov 30 | 280 days | Jan 16 – Jan 30 | Jan 30 – Feb 16 |
| Zone 10 | Jan 30 | Dec 15 | 330 days | Dec 26 – Jan 9 | Jan 9 – Jan 26 |
When to plant swiss chard in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Arizona (this page) | March 15 | Feb 22 – Mar 11 |
| New Mexico | April 20 | Mar 30 – Apr 16 |
Questions gardeners in Arizona ask
When is the best time to plant swiss chard in Arizona?
Plant swiss chard transplants outdoors in Arizona between February 22 and March 11. 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 swiss chard seeds indoors in Arizona?
Start seeds indoors between February 8 and February 22, about 4 weeks before the last frost, so the seedlings are ready to plant out from February 22.
Can I plant swiss chard in the fall in Arizona?
Yes. For a fall crop, sow between August 27 and September 13, so the crop matures in cool weather before Arizona's first frost around November 15.
When will swiss chard planted in Arizona be ready to harvest?
Planted on time, swiss chard is usually ready from about April 20 to April 30, 50-60 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.