The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to estimate when it's a good idea to plant corn by using the USDA zone info for Ottumwa.

Planting Calendar for Corn

Frost tolerance for corn:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You should not plant corn until after the last frost because they are not cold tolerant.

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

The last month that you can plant corn and expect a good harvest is probably August. If you wait any later than that and your corn may not have a chance to fully mature. Starting your corn indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Ottumwa. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ottumwa and it will vary from year to year. Half of the time in Ottumwa last frost occurs after April 15 so make sure that you are ready to protect your corn in the event of a surprise late frost.

USDA Zone Info for Ottumwa

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ottumwa

You may be interested in your other planting guides for Ottumwa.