One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Thief River Falls you should be able to figure out when to plant lisianthus.

Planting Calendar for Lisianthus

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

You really shouldn't plant lisianthus until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant lisianthus 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 lisianthus and expect a good harvest is probably August. If you wait any later than that and your lisianthus may not have a chance to really do well. Starting your lisianthus indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of 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.

Just be sure to remember that USDA zone info for Thief River Falls is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Thief River Falls you get a frost after May 15 so make sure that you are ready to protect your lisianthus 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.