One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. 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 you can plant blue throatwort is to use the USDA zone info for Rockford.

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 require warm weather it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant blue throatwort in Rockford 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. 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

The average date of last frost is April 15 in Rockford. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Rockford is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Rockford you get surprised by a frost after April 15 be ready to cover your blue throatwort in the event of a surprise late frost.

USDA Zone Info for Rockford

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 Rockford

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