When to Plant Corn in Sullivan, IL

One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

By using the USDA zone info for Sullivan you should be able to estimate when it's the best time to plant corn.


Planting Calendar for Corn

Frost tolerance for corn: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

Since corn are not cold tolerant you need to wait until after all chance of frost has passed before you can plant them.

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

The earliest that you can plant corn in Sullivan 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 grow to maturity. Starting your corn indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Sullivan. It might get as low as -10°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Sullivan and it changes from year to year. Since half of the time in Sullivan there is a last frost after April 15 be ready to protect your corn in the event of a surprise late frost.

USDA Zone Info for Sullivan

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Sullivan

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