The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's a good idea to plant flower-of-an-hour in Ontario by referring to the USDA zone info.

Planting Calendar for Flower-of-an-Hour

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

Since flower-of-an-hour do ok in moderate cold you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant flower-of-an-hour in Ontario is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant flower-of-an-hour and expect a good harvest is probably August. Any later than that and your flower-of-an-hour may not have a chance to fully mature. Starting your flower-of-an-hour indoors is a great way to get them started a little bit 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 USDA zone info for Ontario is just an average and the actual date of last frost changes from year to year. Since half of the time in Ontario it frosts late in the year after April 15 be ready to cover your flower-of-an-hour 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.