One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when you can plant blue throatwort in Zone 9b by reviewing 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.

Blue Throatwort are not cold tolerant which tells us that you really should 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 9b 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. If you wait any later than that and your blue throatwort may not have a chance to fully mature. If you are starting your blue throatwort indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Zone 9b the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 9b and it will vary from year to year. Since half of the time in Zone 9b you get a frost after February 15 be ready to cover your blue throatwort in the event of a late frost.

USDA Zone Info for Zone 9b

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Zone 9b

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