The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when it's a good idea to plant blue throatwort by looking at the USDA zone info for Spirit Lake.

Planting Calendar for Blue Throatwort

Frost tolerance for blue throatwort:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since blue throatwort require warm weather you have to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant blue throatwort in Spirit Lake 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 blue throatwort and expect a good harvest is probably August. You probably don't want to wait any later than that or else your blue throatwort may not have a chance to really do well. Starting your blue throatwort indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Spirit Lake the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Spirit Lake is not always accurate the actual date of last frost is different every year. Half of the time in Spirit Lake last frost occurs after April 15 so just be sure to be ready to cover your blue throatwort if you have a late frost.

USDA Zone Info for Spirit Lake

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Spirit Lake

You may be interested in your other planting guides for Spirit Lake.