When to plant potatoes in California
California’s average last spring frost is February 20, and the first fall frost typically arrives around December 1 — about 284 frost-free days (USDA zones 5a, 6b, 7b, 8b, 9b, 10a, 10b). Potato needs 70–120 days to mature, which fits comfortably within California's growing season.
California 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 potatoes in California: the short answer
For a spring planting, sow Feb 1 – Feb 20. Seeds germinate in soil from 45 to 80°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 potatoes in California, step by step
- Prepare the bed. They need at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 4.8 and 6.5. Dig in compost before planting.
- Sow outdoors (Feb 1 – Feb 20). Space plants about 12 inches apart in rows 32 inches apart, sowing seed 4 inches deep. It tolerates a light frost but not a hard freeze. As a cool-season crop it does best before summer heat arrives in California.
- 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: Colorado potato beetle, flea beetle, wireworm, aphids. Diseases and disorders: late blight, early blight, common scab, blackleg.
- Harvest (from about Apr 17 – Jun 6). Potato takes 70-120 days to reach harvest. Plant certified seed potatoes, not grocery-store ones. Hill soil or mulch over the stems as they grow to stop greening. New potatoes ~10 weeks in; storage potatoes after the tops die back.
Figures come from our crop data; dates use California’s average frost dates. More in the full potato growing guide.
Potato planting dates by USDA zone in California
California spans USDA zones 5a, 6b, 7b, 8b, 9b, 10a, 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 potato dates shift with them.
| Zone | Last frost | First frost | Season | Start indoors | Plant potato |
|---|---|---|---|---|---|
| Zone 5 | Apr 30 | Oct 5 | 160 days | - | Apr 11 – Apr 30 |
| Zone 6 | Apr 15 | Oct 15 | 185 days | - | Mar 27 – Apr 15 |
| Zone 7 | Apr 5 | Oct 25 | 200 days | - | Mar 17 – Apr 5 |
| Zone 8 | Mar 20 | Nov 5 | 230 days | - | Mar 1 – Mar 20 |
| Zone 9 | Feb 20 | Nov 30 | 280 days | - | Feb 1 – Feb 20 |
| Zone 10 | Jan 30 | Dec 15 | 330 days | - | Jan 11 – Jan 30 |
Questions gardeners in California ask
When is the best time to plant potatoes in California?
Sow potatoes in California between February 1 and February 20. That timing is set by California's average last spring frost of February 20; California spans several climates, so cooler and higher parts of the state run later.
When will potatoes planted in California be ready to harvest?
Planted on time, potatoes are usually ready from about April 17 to June 6, 70-120 days after sowing.
When is the last frost in California?
On average around February 20, with the first fall frost around December 1 - about 284 frost-free days. Your town may differ by two weeks or more.