The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when you can plant flowering kale by using the USDA zone info for Ottawa.

Planting Calendar for Flowering Kale

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

Since flowering kale do well in moderate cold you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant flowering kale in Ottawa 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

On average the last frost when the weather gets warmer is on April 15 in Ottawa. You should expect an average low temperature of -10°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ottawa and it can change quite a bit from year to year. Half of the time in Ottawa there is a last frost after April 15 so make sure that you are ready to cover your flowering kale in the event of one of those late frosts.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ottawa

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