The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for International Falls can be read to determine when it's possible to plant campanula.

Planting Calendar for Campanula

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

Campanula are one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than plants that are more sensitive to the cold.

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

Last Frost Date

In International Falls the average date of last frost happens on May 15. It might get as low as -40°F during the coldest months of winter.

Since the USDA zone info for International Falls may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in International Falls there is a last frost after May 15 be ready to protect your campanula in the event of a late frost.

USDA Zone Info for International Falls

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-40°F
Highest Expected Low	-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in International Falls

You may be interested in your other planting guides for International Falls.