Plant Corn in Zone 4b
Seed-starting, transplant & harvest dates for USDA Zone 4b
Zone 4b averages 146 frost-free days, running from a last spring frost around May 5 to a first fall frost around September 28. Corn needs roughly 75 days from planting out to first harvest, so it uses about 51 percent of that window. Corn is a tender crop, which is what decides where in the window it belongs.
Corn resents transplanting and hates cold soil, so direct sow around May 12, after the Zone 4b last frost has passed and the soil has warmed.
Fall planting: corn in Zone 4b
Corn has no useful fall window in Zone 4b. Sweet corn pollinates badly in short, cool autumn days, so a fall planting rarely fills out.
Sweet corn pollinates badly in short, cool autumn days, so a fall planting rarely fills out.
Fall dates are counted backward from the Zone 4b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.
Spring vs fall corn in Zone 4b
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | May 12 | May 12 | Jul 26 |
| Fall | — | — | — |
Corn in nearby zones
Further reading on corn
- Soil temperature for planting seeds
The soil temperature corn needs before it will germinate.
- Companion planting chart
What to plant with corn and what to keep away from it.
Other crops in Zone 4b
Frequently asked questions
When should I start corn in Zone 4b?
Direct sow outdoors around May 12.
Can I direct sow corn in Zone 4b?
Yes, direct sow around May 12.
Can I plant corn in the fall in Zone 4b?
Corn has no useful fall window in Zone 4b. Sweet corn pollinates badly in short, cool autumn days, so a fall planting rarely fills out.
Will corn survive frost in Zone 4b?
No. Corn is a tender crop and a single light frost ends it, so every Zone 4b planting has to finish before the average first frost.