When to Plant Sweet Corn
Sow sweet corn outside 1 to 4 weeks after your last frost.
Sweet corn at a glance
- Sow outside
- 1 to 4 weeks after your last frost
- Time to harvest
- 65 to 90 days from sowing
- Harvest lasts
- about 3 weeks
- Spacing
- 4 per square foot
- Frost
- Tender: frost kills it
Growing sweet corn
Sweet corn needs warm soil, full sun, rich soil and a good drink, especially when the tassels appear. Grow one kind at a time, or time sowings apart, since some supersweet types lose sweetness if they cross with other corn.
Dates by hardiness zone
Typical dates for each zone; your ZIP code gives your own.
| Zone | Sow | Harvest |
|---|---|---|
| Zone 3a | Jun 4–25 | Aug 8 – Sep 14Pick a fast variety. |
| Zone 3b | May 24 – Jun 14 | Jul 28 – Sep 12 |
| Zone 4a | May 19 – Jun 9 | Jul 23 – Sep 7 |
| Zone 4b | May 15 – Jun 5 | Jul 19 – Sep 3 |
| Zone 5a | May 10–31 | Jul 14 – Aug 29 |
| Zone 5b | May 8–29 | Jul 12 – Aug 27 |
| Zone 6a | May 6–27 | Jul 10 – Aug 25 |
| Zone 6b | Apr 30 – May 21 | Jul 4 – Aug 19 |
| Zone 7a | Apr 23 – May 14 | Jun 27 – Aug 12 |
| Zone 7b | Apr 12 – May 3 | Jun 16 – Aug 1 |
| Zone 8a | Apr 5–26 | Jun 9 – Jul 25 |
| Zone 8b | Mar 24 – Apr 14 | May 28 – Jul 13 |
| Zone 9a | Mar 9–30 | May 13 – Jun 28 |
| Zone 9b | Feb 15 – Mar 8Nights are still cool before mid-February, so this starts a little later. | Apr 21 – Jun 6 |
| Zone 10a | Feb 15 – Mar 8 | Apr 21 – Jun 6 |
| Zones 10b–11b | Frost is rare here, so sweet corn can go in from late winter, and again in late summer for a fall crop. | |
Good neighbors
Keep apart from
Questions about sweet corn
How many ears does a corn plant give?
Usually one or two good ears per stalk. Plan on a block of plants, and sow a second block a couple of weeks later to stretch the harvest.
When is sweet corn ready?
When the silks turn brown and dry, and a kernel pressed with a fingernail gives milky juice. Corn is sweetest right after picking, so pick it just before cooking.
