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.

You can estimate when it's a good idea to plant red cabbage in Ottawa by looking at the USDA zone info.

Planting Calendar for Red cabbage

Frost tolerance for red cabbage:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Red cabbage are very cold tolerant which tells us that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant red cabbage 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 red cabbage and expect a good harvest is probably September. You probably don't want to wait any later than that or else your red cabbage may not have a chance to grow to maturity. Starting your red cabbage indoors is a great way to get them started a little bit 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 -15°F in the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Ottawa and it will vary from year to year. Since half of the time in Ottawa you get a frost after April 15 be ready to protect your red cabbage if you have a surprise late frost.

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.