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.

You can figure out when it's the best time to plant corn in Ottawa by reviewing the USDA zone info.

Planting Calendar for Corn

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

You can not plant corn until after the last frost because they are not cold tolerant.

The earliest that you can plant corn in Ottawa 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. Any later than that and your corn may not have a chance to grow to maturity. Starting your corn indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ottawa. In the coldest months of winter you can expect an average low temperature of -15°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Ottawa and it will vary from year to year. Half of the time in Ottawa there is a last frost after April 15 so be sure to be ready to cover your corn if you have one of those late frosts.

USDA Zone Info for Ottawa

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 Ottawa

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