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

The USDA zone info for Red Bluff should be looked at to estimate when it's a good idea 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 has passed.

Since blue throatwort require warm weather it's 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 Red Bluff 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. Any later than that and your blue throatwort may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your blue throatwort indoors.

Last Frost Date

In Red Bluff the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Red Bluff and it will vary from year to year. Half of the time in Red Bluff it frosts late in the year after February 15 so be sure to be ready to cover your blue throatwort in the event of one of those late frosts.

USDA Zone Info for Red Bluff

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 Red Bluff

You may be interested in your other planting guides for Red Bluff.