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

You will be able to determine when it's a good idea to plant black eyed susans by checking out the USDA zone info for Ontario.

Planting Calendar for Black Eyed Susans

Frost tolerance for black eyed susans:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant black eyed susans until after the last frost because they are not cold tolerant.

The earliest that you can plant black eyed susans in Ontario 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 black eyed susans and expect a good harvest is probably August. If you wait any later than that and your black eyed susans may not have a chance to fully mature. You can get started a few weeks earlier by starting your black eyed susans indoors.

Last Frost Date

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

Since the USDA zone info for Ontario is an average the actual date of last frost is different every year. Half of the time in Ontario you get a frost after April 15 so just be sure to be ready to protect your black eyed susans in the event of a surprise late frost.

USDA Zone Info for Ontario

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 Ontario

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