One of the first steps you take when you are determining your gardening schedule is find your 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.

The first opportunity to plant sweet corn in Janesville can be estimated by reviewing 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.

Since sweet corn are barely cold tolerant you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant sweet corn in Janesville is March. However, you really should wait until April 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 really do well. Starting your sweet corn indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Janesville. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Janesville is not always accurate the actual date of last frost changes from year to year. Half of the time in Janesville last frost occurs after April 15 so make sure that you are ready to protect your sweet corn if you have one of those late frosts.

USDA Zone Info for Janesville

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Janesville

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