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 looking at the USDA zone info for Thief River Falls you will be able to estimate when it's the best time to plant doronicum.

Planting Calendar for Doronicum

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

Since doronicum are one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant doronicum 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 doronicum and expect a good harvest is probably August. If you wait any later than that and your doronicum may not have a chance to fully mature. You can get started a little bit earlier by starting your doronicum indoors.

Last Frost Date

In Thief River Falls the average date of last frost happens on May 15. It might get as low as -35°F during the coldest months of winter.

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 will vary from year to year. Since half of the time in Thief River Falls it frosts late in the year after May 15 be ready to protect your doronicum 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.