One of the best tools that you have as gardeners to help us figure out 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.

By referring to the USDA zone info for Ontario you will be able to figure out when you can plant begonias.

Planting Calendar for Begonias

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

Since begonias are not cold tolerant it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant begonias 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 begonias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your begonias may not have a chance to grow to maturity. If you are starting your begonias indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ontario. In the coldest months of winter you should expect an average low temperature of -15°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Ontario and it is different every year. Since half of the time in Ontario there is a last frost after April 15 be ready to cover your begonias if you have a 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.