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.

The USDA zone info for Warrenville should be reffered to in order to figure out when it's possible 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 has passed.

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

The earliest that you can plant blue throatwort in Warrenville 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. You can get started a little bit earlier by starting your blue throatwort indoors.

Last Frost Date

In Warrenville 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.

Since the USDA zone info for Warrenville is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Warrenville last frost occurs after April 15 be ready to protect your blue throatwort if you have a late frost.

USDA Zone Info for Warrenville

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 Warrenville

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