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

The earliest that you can plant blue throatwort in Louisville should be determined by looking at the USDA zone info.

Planting Calendar for Blue Throatwort

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

You really shouldn't plant blue throatwort until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant blue throatwort in Louisville 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 fully mature. Starting your blue throatwort indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Louisville. It might get as low as -10°F during the coldest months of winter.

Keep in mind that USDA zone info for Louisville is just an average and the actual date of last frost changes from year to year. Half of the time in Louisville it frosts late in the year after April 15 so always be ready to cover your blue throatwort if you have a surprise late frost.

USDA Zone Info for Louisville

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Louisville

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