Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's possible to plant sweet corn by using the USDA zone info for Caribou.

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 a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant sweet corn in Caribou 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 all chance of frost has passed is on May 15 in Caribou. In the coldest months of winter you should expect an average low temperature of -30°F.

Keep in mind that USDA zone info for Caribou is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Caribou you get a 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 Caribou

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Caribou

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