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.

A common way of making a decision about when it's the best time to plant corn is to refer to the USDA zone info for Joliet.

Planting Calendar for Corn

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

Since corn are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant corn in Joliet 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. You probably don't want to wait any later than that or else your corn may not have a chance to fully mature. If you are starting your corn indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Joliet. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Joliet may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Joliet you get surprised by a frost after April 15 so make sure that you are prepared to protect your corn in the event of a surprise late frost.

USDA Zone Info for Joliet

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 Joliet

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