One of the first steps you take when you are determining your gardening schedule is find your 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 figure out when it's the best time to plant calibrachoa by looking at the USDA zone info.

Planting Calendar for Calibrachoa

Frost tolerance for calibrachoa:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since calibrachoa do ok in moderate cold you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant calibrachoa in Ontario is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant calibrachoa and expect a good harvest is probably September. Any later than that and your calibrachoa may not have a chance to really do well. You can get started a couple of weeks earlier by starting your calibrachoa indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Ontario. It might get as low as 30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Ontario is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Ontario you get a frost after January 31 so just be sure to be ready to cover your calibrachoa if you have one of those late frosts.

USDA Zone Info for Ontario

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Ontario

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