The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Willmar you can estimate when to plant sweet corn by looking at the USDA zone info.

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 mild cold which tells us that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant sweet corn in Willmar 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. You probably don't want to wait any later than that or else your sweet corn may not have a chance to grow to maturity. If you are starting your sweet 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 is on May 15 in Willmar. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind 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 Willmar and it can change quite a bit from year to year. Since half of the time in Willmar you get surprised by a frost after May 15 be ready to protect your sweet corn if you have a late frost.

USDA Zone Info for Willmar

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 Willmar

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