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 USDA zone info for Zone 9b can be reffered to in order to figure out when you can plant centaurea.

Planting Calendar for Centaurea

Frost tolerance for centaurea:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Centaurea are one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant centaurea in Zone 9b is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant centaurea and expect a good harvest is probably October. If you wait any later than that and your centaurea may not have a chance to fully mature. Starting your centaurea indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Zone 9b. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Zone 9b is not always accurate the actual date of last frost changes from year to year. Since half of the time in Zone 9b you get surprised by a frost after February 15 be ready to protect your centaurea 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.