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.

In Toronto you can estimate when it's possible to plant four-o-clock flower by using the USDA zone info.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Four-o-clock flower require warm weather which tells us that it's necessary 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 four-o-clock flower in Toronto 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 four-o-clock flower and expect a good harvest is probably August. Any later than that and your four-o-clock flower may not have a chance to really do well. You can get started a little bit earlier by starting your four-o-clock flower indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Toronto. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Toronto may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Toronto last frost occurs after April 15 so just be sure to be ready to cover your four-o-clock flower if you have a late frost.

USDA Zone Info for Toronto

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Toronto

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