Before planting it is a good idea to find your USDA Zone info to figure out 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 looking at the USDA zone info for Greencastle you should be able to determine when you can plant blue throatwort.

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.

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

The earliest that you can plant blue throatwort in Greencastle 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Greencastle. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Greencastle is an average the actual date of last frost is different every year. Since half of the time in Greencastle you get a frost after April 15 be ready to cover your blue throatwort in the event of a surprise late frost.

USDA Zone Info for Greencastle

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 Greencastle

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