One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when to plant garden cress is to examine the USDA zone info for Ontario.

Planting Calendar for Garden cress

Frost tolerance for garden cress:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's not a good idea to plant garden cress until after the last frost has passed because they require warm weather.

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

The last month that you can plant garden cress and expect a good harvest is probably August. If you wait any later than that and your garden cress may not have a chance to grow to maturity. If you are starting your garden cress indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Ontario the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Ontario and it is different every year. Since half of the time in Ontario there is a last frost after April 15 be ready to cover your garden cress in the event of one of those late frosts.

USDA Zone Info for Ontario

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Ontario

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