Arizona · zones 5b–10a
When to plant sweet corn in Arizona.
Sow between Feb 12 to May 14 in a typical year, keyed to Arizona's median last frost around Feb 5. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Sweet Corn dates for a typical Arizona season.
Direct sow
Feb 12 to May 14
Keyed to the ~Feb 5 last frost. Sow 1.5" deep, 12" apart.
Harvest
~75 days later
~1 lb per plant over ~1 weeks.
Arizona spans more than one climate: Zone 9 is the most common zone, but the state runs 5b to 10a. 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 Arizona: watch for
The pests that find sweet corn here.
With about 283 frost-free days, sweet corn spends longer in the ground here than in most of the country, which widens the window in which corn earworm can find it. Scout weekly from midseason and act on the first signs.
Caterpillars feeding down in the tip of the ear.
Organic fix: A few drops of oil on the silk; Bt on the silks.
Clusters on the tassels and upper leaves.
Organic fix: Usually minor; insecticidal soap if heavy.
Fall armyworm
Ragged holes through the unfurling whorl leaves, with sawdust-like droppings down in the funnel.
Organic fix: Check whorls weekly before tassel; Bt or spinosad while the caterpillars are still small.
Cinnamon-brown powdery pustules breaking out on BOTH sides of the same leaf, lower leaves first, darkening as they age.
Organic fix: Water at the ground rather than overhead, and choose resistant varieties next season; sprays are rarely worth it.
Your season math: Arizona gives sweet corn about 283 frost-free days, and it needs roughly 75 days to a first harvest. That fits about 21 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting sweet corn in Arizona: questions
When should I plant sweet corn in Arizona?+
In a typical Arizona year, sow sweet corn between Feb 12 to May 14, keyed to the state's median last frost around Feb 5. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Arizona?+
Arizona spans zones 5b–10a, mostly zone 9. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many sweet corn 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.