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.

A common way of making a decision about when it's the best time to plant garden cress is to use the USDA zone info for Ottawa.

Planting Calendar for Garden cress

Frost tolerance for garden cress:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant garden cress until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant garden cress in Ottawa 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 really do well. If you are starting your garden cress indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Ottawa. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Ottawa may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Ottawa there is a last frost after April 15 be ready to protect your garden cress 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.