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.

You can figure out when to plant rock cress in Ontario by referring to the USDA zone info.

Planting Calendar for Rock Cress

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

You can plant rock cress quite a bit earlier in the year because they do well in cold.

The earliest that you can plant rock cress in Ontario is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant rock cress and expect a good harvest is probably October. You probably don't want to wait any later than that or else your rock cress may not have a chance to really do well. You can get started a couple of weeks earlier by starting your rock cress indoors.

Last Frost Date

In Ontario the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

Keep in mind that USDA zone info for Ontario is just an average and the actual date of last frost changes from year to year. Half of the time in Ontario it frosts late in the year after January 31 so make sure that you are prepared to protect your rock cress if you have a surprise late frost.

USDA Zone Info for Ontario

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Ontario

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