Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Thief River Falls you will be able to figure out when it's the best time to plant sorrel.

Planting Calendar for Sorrel

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

Since sorrel are one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant sorrel 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 sorrel and expect a good harvest is probably August. Any later than that and your sorrel may not have a chance to really do well. If you are starting your sorrel indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Thief River Falls. 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 is different every year. Since half of the time in Thief River Falls you get a frost after May 15 be ready to protect your sorrel in the event of 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.