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

The earliest that you can plant kohlrabi in Ontario should be estimated by checking out the USDA zone info.

Planting Calendar for Kohlrabi

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

Kohlrabi do well in moderate cold which tells us that you can plant them earlier than plants that are more sensitive to the cold.

The earliest that you can plant kohlrabi 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 kohlrabi and expect a good harvest is probably September. If you wait any later than that and your kohlrabi may not have a chance to really do well. If you are starting your kohlrabi indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ontario. It might get as low as -15°F during the coldest months of winter.

Always keep in mind 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 Ontario and it changes from year to year. Since half of the time in Ontario you get a frost after April 15 be ready to cover your kohlrabi 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.