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.

In Ottawa you can determine when it's a good idea to plant romanesco by looking at the USDA zone info.

Planting Calendar for Romanesco

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

You can plant romanesco a little bit earlier in the year because they do well in moderate cold.

The earliest that you can plant romanesco 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 romanesco and expect a good harvest is probably September. Any later than that and your romanesco may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your romanesco indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Ottawa is an average and the actual date of last frost changes from year to year. Half of the time in Ottawa you get a frost after April 15 so make sure that you are prepared to cover your romanesco if you have 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.