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.

The best time to plant tithonia in Thief River Falls should be determined by using the USDA zone info.

Planting Calendar for Tithonia

Frost tolerance for tithonia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You really shouldn't plant tithonia until after all chance of frost has passed because they do not do well in cold weather.

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

The last month that you can plant tithonia and expect a good harvest is probably August. If you wait any later than that and your tithonia may not have a chance to fully mature. Starting your tithonia indoors is a great way to get them started a little bit earlier.

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.

Since the USDA zone info for Thief River Falls is not always accurate the actual date of last frost is different every year. Half of the time in Thief River Falls you get a frost after May 15 so just be sure to be ready to cover your tithonia 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.