When to Plant Sweet corn in De Witt, IA

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for De Witt can be looked at to determine when it's a good idea to plant sweet corn.


Planting Calendar for Sweet corn

Frost tolerance for sweet corn: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Sweet corn do ok in moderate cold which tells us that you can start planting them slightly earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant sweet corn
Possibly ok, but a risky time to plant sweet corn
Probably not a good time to plant sweet corn

The earliest that you can plant sweet corn in De Witt is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant sweet corn and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet corn may not have a chance to fully mature. If you are starting your sweet corn indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In De Witt the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for De Witt may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in De Witt you get a frost after April 15 be ready to protect your sweet corn if you have a late frost.

USDA Zone Info for De Witt

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in De Witt

You may be interested in your other planting guides for De Witt.