One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of making a decision about when it's a good idea to plant salvia is to look at the USDA zone info for Thief River Falls.

Planting Calendar for Salvia

Frost tolerance for salvia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant salvia slightly earlier in the year because they are barely cold tolerant.

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

The last month that you can plant salvia and expect a good harvest is probably August. Any later than that and your salvia may not have a chance to really do well. If you are starting your salvia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Thief River Falls. In the coldest months of winter you should expect an average low temperature of -35°F.

Since the USDA zone info for Thief River Falls is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Thief River Falls you get surprised by a frost after May 15 be ready to cover your salvia in the event of 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.