One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Ontario you can estimate when it's a good idea to plant portulaca by using the USDA zone info.

Planting Calendar for Portulaca

Frost tolerance for portulaca:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably a bad idea to plant portulaca until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant portulaca 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 portulaca and expect a good harvest is probably August. If you wait any later than that and your portulaca may not have a chance to grow to maturity. Starting your portulaca indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Ontario the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Ontario is not always accurate the actual date of last frost is different every year. Since half of the time in Ontario it frosts late in the year after April 15 be ready to protect your portulaca in the event of a surprise late frost.

USDA Zone Info for Ontario

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 Ontario

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