One of the best tools that you have as gardeners to help us determine 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.

One way of making a decision about when you can plant sweet corn is to refer to the USDA zone info for Northfield.

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.

You can plant sweet corn slightly earlier in the year because they are barely cold tolerant.

The earliest that you can plant sweet corn in Northfield 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 sweet corn and expect a good harvest is probably August. Any later than that and 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 little bit earlier.

Last Frost Date

In Northfield the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for Northfield is an average and the actual date of last frost will vary from year to year. Half of the time in Northfield there is a last frost after May 15 so make sure that you are prepared to protect your sweet corn if you have one of those late frosts.

USDA Zone Info for Northfield

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Northfield

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