One of the best tools that you have as gardeners to help us determine 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.

In International Falls you can determine when it's the best time to plant anchusa by referring to the USDA zone info.

Planting Calendar for Anchusa

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

Since anchusa are very cold tolerant you can plant them earlier in the year than other plants that might not handle the cold.

The earliest that you can plant anchusa 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 anchusa and expect a good harvest is probably August. Any later than that and your anchusa may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your anchusa indoors.

Last Frost Date

On average the last frost has passed is on May 15 in International Falls. In the coldest months of winter you should expect an average low temperature of -40°F.

Since the USDA zone info for International Falls is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in International Falls you get a frost after May 15 be ready to protect your anchusa if you have one of those late frosts.

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.