Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

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

Planting Calendar for Mecardonia

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

It's a bad idea to plant mecardonia until after the last frost has passed because they require warm weather.

The earliest that you can plant mecardonia 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 mecardonia and expect a good harvest is probably August. Any later than that and your mecardonia may not have a chance to fully mature. If you are starting your mecardonia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Ontario is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Ontario it frosts late in the year after April 15 so make sure that you are ready to cover your mecardonia 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.