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.

One way of determining when it's a good idea to plant blue throatwort is to examine the USDA zone info for Charlestown.

Planting Calendar for Blue Throatwort

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

Blue Throatwort are not cold tolerant which means that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant blue throatwort in Charlestown 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. If you wait any later than that and your blue throatwort may not have a chance to grow to maturity. 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 Charlestown the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Always keep in mind that USDA zone info for Charlestown is an average and the actual date of last frost will vary from year to year. Since half of the time in Charlestown it frosts late in the year after April 15 be ready to protect your blue throatwort in the event of one of those late frosts.

USDA Zone Info for Charlestown

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Charlestown

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