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.

By using the USDA zone info for Keller it's a good idea to determine when it's the best time 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.

Since blue throatwort do not do well in cold weather it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant blue throatwort in Keller 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. You probably don't want to wait any later than that or else your blue throatwort may not have a chance to really do well. Starting your blue throatwort indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Keller the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Keller is just an average the actual date of last frost will vary from year to year. Half of the time in Keller you get a frost after March 15 so be sure to be ready to protect your blue throatwort if you have a surprise late frost.

USDA Zone Info for Keller

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Keller

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