The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Thief River Falls it's a good idea to estimate when to plant lupine.

Planting Calendar for Lupine

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

You can plant lupine a bit earlier in the year because they do well in moderate cold.

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

Last Frost Date

In Thief River Falls 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.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Thief River Falls and it changes from year to year. Since half of the time in Thief River Falls you get surprised by a frost after May 15 be ready to cover your lupine if you have a surprise 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.