Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when it's a good idea to plant iberis by referring to the USDA zone info for Ontario.

Planting Calendar for Iberis

Frost tolerance for iberis:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Iberis are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than more sensitive plants.

The earliest that you can plant iberis 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 iberis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your iberis may not have a chance to grow to maturity. Starting your iberis 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 can expect an average low temperature of -15°F.

Since the USDA zone info for Ontario is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Ontario you get surprised by a frost after April 15 be ready to protect your iberis 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.