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 Thief River Falls you can determine when you can plant flax by checking out the USDA zone info.

Planting Calendar for Flax

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

Flax can survive in mild cold which means that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant flax 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 flax and expect a good harvest is probably August. If you wait any later than that and your flax may not have a chance to fully mature. If you are starting your flax indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Thief River Falls. You can expect an average low temperature of -35°F in the coldest months of winter.

Remember that USDA zone info for Thief River Falls is not always accurate and the actual date of last frost is different every year. Since half of the time in Thief River Falls you get surprised by a frost after May 15 be ready to cover your flax if you have one of those late frosts.

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.