California · zones 7a–10b
When to plant potatoes in California.
Sow between Dec 7 to Jan 9 in a typical year, keyed to California's median last frost around Jan 14. A second, fall sowing fits Aug 26 to Sep 8. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Potatoes dates for a typical California season.
Direct sow
Dec 7 to Jan 9
Keyed to the ~Jan 14 last frost. Sow 4" deep, 12" apart.
Fall round
Aug 26 to Sep 8
Counted back from the ~Dec 14 first frost.
Harvest
~90 days later
~3 lb per plant over ~1 weeks.
California spans more than one climate: Zone 10 is the most common zone, but the state runs 7a to 10b. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
In California: watch for
The pests that find potatoes here.
With about 334 frost-free days, potato spends longer in the ground here than in most of the country, which widens the window in which colorado potato beetle can find it. Scout weekly from midseason and act on the first signs.
Striped beetles and orange grubs eating the leaves.
Organic fix: Handpick adults, crush the orange egg clusters, dust with diatomaceous earth.
Dark greasy blotches after cool, wet spells.
Organic fix: Pull infected plants fast, keep leaves dry, use neem as a preventive.
Common scab
Rough, corky patches on the skin, raised on some tubers and sunk into pits on others.
Organic fix: Keep the bed evenly moist through the weeks right after tubers set, rotate away from potatoes, and pick a scab-resistant variety next time.
Your season math: California gives potatoes about 334 frost-free days, and it needs roughly 90 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting potatoes in California: questions
When should I plant potatoes in California?+
In a typical California year, sow potatoes between Dec 7 to Jan 9, keyed to the state's median last frost around Jan 14. There's also a fall window: Aug 26 to Sep 8. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is California?+
California spans zones 7a–10b, mostly zone 10. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many potatoes plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.