Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant blue throatwort in Zone 9a can 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 all chance of frost has passed.

Blue Throatwort require warm weather which tells us that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant blue throatwort in Zone 9a is March. However, you really should wait until April 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 September. 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. You can get started a few weeks earlier by starting your blue throatwort indoors.

Last Frost Date

In Zone 9a the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Zone 9a is an average the actual date of last frost will vary from year to year. Half of the time in Zone 9a last frost occurs after February 15 so make sure that you are prepared to cover your blue throatwort in the event of a surprise late frost.

USDA Zone Info for Zone 9a

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Zone 9a

You may be interested in your other planting guides for Zone 9a.