One of the first steps you take when you are making a decision about 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.

The first opportunity to plant salpiglossis in Thief River Falls should be determined by checking out the USDA zone info.

Planting Calendar for Salpiglossis

Frost tolerance for salpiglossis:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably a bad idea to plant salpiglossis until after the last frost because they require warm weather.

The earliest that you can plant salpiglossis 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 salpiglossis and expect a good harvest is probably August. If you wait any later than that and your salpiglossis may not have a chance to fully mature. Starting your salpiglossis indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Thief River Falls. It might get as low as -35°F during the coldest months of winter.

Since the USDA zone info for Thief River Falls may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Thief River Falls there is a last frost after May 15 so always be ready to protect your salpiglossis in the event of a surprise 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.