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.

It's possible to figure out when to plant ajuga by reviewing the USDA zone info for Ontario.

Planting Calendar for Ajuga

Frost tolerance for ajuga:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Ajuga do well in cold which tells us that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant ajuga 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 ajuga and expect a good harvest is probably September. Any later than that and your ajuga may not have a chance to fully mature. You can get started a little bit earlier by starting your ajuga indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Ontario. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Ontario is not always accurate and the actual date of last frost is different every year. Since half of the time in Ontario you get surprised by a frost after April 15 be ready to protect your ajuga if you have one of those late frosts.

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.