Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant asters in Thief River Falls should be figured out by looking at the USDA zone info.

Planting Calendar for Asters

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

Asters do well in moderate cold which tells us that you can get them planted earlier than more sensitive plants.

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

Last Frost Date

In Thief River Falls the average date of last frost happens on May 15. 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. Half of the time in Thief River Falls you get a frost after May 15 so be sure to be ready to cover your asters if you have 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.