Before planting it is a good idea to find your USDA Zone info to estimate 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.

By checking out the USDA zone info for Willmar you will be able to estimate when it's the best time to plant blue throatwort.

Planting Calendar for Blue Throatwort

Frost tolerance for blue throatwort:	Not tolerant of frost.
When to plant:	After the last frost.

Since blue throatwort are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

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

Last Frost Date

On average the last frost has passed is on May 15 in Willmar. You can expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Willmar is just an average the actual date of last frost will vary from year to year. Half of the time in Willmar you get surprised by a frost after May 15 so make sure that you are ready to cover your blue throatwort if you have a late frost.

USDA Zone Info for Willmar

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Willmar

You may be interested in your other planting guides for Willmar.