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

The first opportunity to plant cauliflower in Ottawa can be determined by looking at the USDA zone info.

Planting Calendar for Cauliflower

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

Cauliflower tend to make it in mild cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant cauliflower 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 cauliflower and expect a good harvest is probably September. Any later than that and your cauliflower may not have a chance to really do well. You can get started a few weeks earlier by starting your cauliflower indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Ottawa. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Ottawa may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Ottawa it frosts late in the year after April 15 so make sure that you are ready to protect your cauliflower in the event of a surprise late frost.

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.