One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant peonies in Ontario should be determined by looking at the USDA zone info.

Planting Calendar for Peonies

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

Peonies can survive in very little cold which means that 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 peonies 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 peonies and expect a good harvest is probably August. Any later than that and your peonies may not have a chance to really do well. Starting your peonies indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Ontario the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average 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 peonies 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.