The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Thief River Falls you will be able to estimate when it's a good idea to plant celeriac.

Planting Calendar for Celeriac

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

Since celeriac are moderately cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant celeriac 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 celeriac and expect a good harvest is probably August. You probably don't want to wait any later than that or else your celeriac may not have a chance to really do well. You can get started a few weeks earlier by starting your celeriac indoors.

Last Frost Date

On average the last 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.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Thief River Falls and it is different every year. Since half of the time in Thief River Falls there is a last frost after May 15 be ready to protect your celeriac 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.