How to grow sweet corn
Zea mays subsp. mays · Poaceae · Vegetable
When to plant sweet corn: the short answer
Sow outdoors about 1 week after the last frost. Wait until the soil is at least 55°F; sweet corn sprout fastest near 75°F.
Zone 5: sow May 2 – May 21. Zone 7: sow Apr 7 – Apr 26. Zone 9: sow Feb 22 – Mar 13. See every zone.
Sweet Corn is a warm-season vegetable in the Poaceae family, almost always sown straight into the ground where it will grow. It wants full sun (six or more hours of direct light) and plenty of water, especially in hot weather. From sowing to first pick is about 60–100 days. It is killed by frost, so nothing goes outside until the danger has passed and the soil has warmed.
Grower’s note: Plant in a block of at least 4 short rows, not one long row, or the ears fill unevenly. Keep sugar-enhanced and supersweet types isolated from field corn. Succeed by sowing every 2 weeks or planting early/mid/late varieties together.
Sowing
Sow about 1.5″ deep, into soil between 55–95°F — germination is quickest near 75°F. It comes up fast (5–12 days). It does not transplant well, so sow it in its final position rather than starting it in pots.
Spacing & layout
Give each plant about 10″ along the row with roughly 30″ between rows. On a square-foot grid that is 1 per square foot. Allow at least 24″ of loose, workable soil for the roots. It needs more root room than most containers give and does best in the ground.
Fitting it to your season
Sweet Corn needs roughly 60–100 frost-free days to crop. Where the season is shorter than that, start it indoors and choose the earliest-maturing varieties, or grow it in a container you can move under cover on cold nights. In long, hot-summer regions it can often be planted twice — once in spring and again in mid-to-late summer for a fall harvest.
Quick facts
Growth stages: how long sweet corn takes to grow
From sowing to first harvest takes roughly 60-100 days (9-14 weeks), with seedlings appearing after 5-12 days in soil around 75°F.
When to plant sweet corn
When to plant sweet corn by USDA zone
Dates worked out from each zone’s typical frost dates for 2026. Find your zone on the zone map, or pick your state below for dates from its own frost dates. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Last / first frost | Start indoors | Sow or plant out |
|---|---|---|---|
| Zone 3 | May 15 / Sep 15 | - | May 17 – Jun 5 |
| Zone 4 | May 10 / Sep 25 | - | May 12 – May 31 |
| Zone 5 | Apr 30 / Oct 5 | - | May 2 – May 21 |
| Zone 6 | Apr 15 / Oct 15 | - | Apr 17 – May 6 |
| Zone 7 | Apr 5 / Oct 25 | - | Apr 7 – Apr 26 |
| Zone 8 | Mar 20 / Nov 5 | - | Mar 22 – Apr 10 |
| Zone 9 | Feb 20 / Nov 30 | - | Feb 22 – Mar 13 |
| Zone 10 | Jan 30 / Dec 15 | - | Feb 1 – Feb 20 |
Or browse sweet corn planting dates for every state as static pages.
Companions
Pole Bean, Bush Bean, Zucchini / Summer Squash, Winter Squash, Cucumber, Pea
Tomato
Common problems
Pests: corn earworm, European corn borer, corn rootworm, raccoons.
Diseases & disorders: common smut, common rust, Stewart's wilt.
Questions gardeners ask
When should I plant sweet corn?
Sow outdoors about 1 week after the last frost. Wait until the soil is at least 55°F. The table on this page gives dates for each USDA zone, and the planting calendar gives dates for your own state or ZIP code.
How long does sweet corn take to grow?
About 60-100 days from sowing to the first harvest. Seeds germinate in 5-12 days, fastest in soil around 75°F.
How much sun does sweet corn need?
It needs at least six to eight hours of direct sun a day.
What soil pH does sweet corn need?
A soil pH between 5.8 and 7.0. It tolerates fairly acidic soil better than most vegetables. Test before adding lime or sulfur - see the soil pH and testing guide.
How far apart should I plant sweet corn?
Space plants about 10 inches apart in rows 30 inches apart, or 1 per square foot in a square-foot bed. Sow seeds about 1.5 inches deep.
Can I grow sweet corn in a container?
It is not well suited to containers - it needs more root room and space than a pot gives, so grow it in a bed.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.