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

A common way of determining when to plant blue throatwort is to refer to the USDA zone info for Winthrop Harbor.

Planting Calendar for Blue Throatwort

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

Since blue throatwort do not do well in cold weather you need to wait until after the last frost before you can plant them.

The earliest that you can plant blue throatwort in Winthrop Harbor 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. If you are starting your blue throatwort indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Winthrop Harbor the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for Winthrop Harbor is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Winthrop Harbor you get a frost after April 15 be ready to protect your blue throatwort if you have a late frost.

USDA Zone Info for Winthrop Harbor

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Winthrop Harbor

You may be interested in your other planting guides for Winthrop Harbor.