One of the first steps you take when you are figuring out 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 earliest that you can plant anchusa in Thief River Falls can be figured out 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 much earlier in the year than other frost tender plants.

The earliest that you can plant anchusa in Thief River 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. Starting your anchusa indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Thief River Falls the average date of last frost happens on May 15. You should expect an average low temperature of -35°F in the coldest months of winter.

Keep in mind that USDA zone info for Thief River Falls is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Thief River Falls there is a last frost after May 15 be ready to cover your anchusa if you have a late frost.

USDA Zone Info for Thief River Falls

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 Thief River Falls

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