Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant campanula in Zone 3b can be estimated by checking out the USDA zone info.

Planting Calendar for Campanula

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

Since campanula do well in moderate cold you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant campanula 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 campanula and expect a good harvest is probably August. Any later than that and your campanula may not have a chance to really do well. You can get started a little bit earlier by starting your campanula indoors.

Last Frost Date

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

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Zone 3b and it changes from year to year. Half of the time in Zone 3b you get surprised by a frost after May 15 so always be ready to protect your campanula 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.