One of the first steps you take when you are getting a good idea 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.

By reviewing the USDA zone info for Ottawa you should be able to estimate when it's possible to plant iberis.

Planting Calendar for Iberis

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

Since iberis are moderately cold tolerant you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant iberis in Ottawa 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. If you are starting your iberis indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Ottawa the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Ottawa is just an average the actual date of last frost changes from year to year. Half of the time in Ottawa it frosts late in the year after April 15 so just be sure to be ready to protect your iberis in the event of a late frost.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ottawa

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