One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

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

Planting Calendar for Portulaca

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

Portulaca do not do well in cold weather which means that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant portulaca 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 portulaca and expect a good harvest is probably August. You probably don't want to wait any later than that or else your portulaca may not have a chance to really do well. If you are starting your portulaca 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. In the coldest months of winter you can expect an average low temperature of -10°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Ottawa and it will vary from year to year. Since half of the time in Ottawa you get surprised by a frost after April 15 be ready to protect your portulaca in the event of one of those late frosts.

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.