Before planting it is a good idea to find your USDA Zone info to determine 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.

You should be able to determine when to plant chervil by referring to the USDA zone info for Thief River Falls.

Planting Calendar for Chervil

Frost tolerance for chervil:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Chervil tend to make it in mild cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant chervil in Thief River Falls is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant chervil and expect a good harvest is probably August. If you wait any later than that and your chervil may not have a chance to really do well. You can get started a couple of weeks earlier by starting your chervil indoors.

Last Frost Date

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

Remember that USDA zone info for Thief River Falls is just an average and the actual date of last frost changes from year to year. Half of the time in Thief River Falls it frosts late in the year after May 15 so make sure that you are prepared to protect your chervil in the event of 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.