One of the first steps you take when you are figuring out 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.

One way of estimating when it's a good idea to plant flowering kale is to use the USDA zone info for Ontario.

Planting Calendar for Flowering Kale

Frost tolerance for flowering kale:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Flowering Kale can survive in moderate cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant flowering kale in Ontario is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant flowering kale and expect a good harvest is probably September. Any later than that and your flowering kale may not have a chance to really do well. If you are starting your flowering kale indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Ontario is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Ontario there is a last frost after April 15 be ready to cover your flowering kale if you have 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.