One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

The USDA zone info for Zone 3b can be looked at to determine when it's a good idea to plant ajuga.

Planting Calendar for Ajuga

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

Since ajuga are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant ajuga in Zone 3b 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 ajuga and expect a good harvest is probably August. You probably don't want to wait any later than that or else your ajuga may not have a chance to grow to maturity. If you are starting your ajuga indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Zone 3b the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -35°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 3b and it is different every year. Half of the time in Zone 3b you get a frost after May 15 so just be sure to be ready to protect your ajuga if you have a surprise late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in your other planting guides for Zone 3b.