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.

A common way of estimating when it's possible to plant centaurea is to use the USDA zone info for Scottsdale.

Planting Calendar for Centaurea

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

Centaurea do well in moderate cold which tells us that you can start planting them earlier than other frost tender plants.

The earliest that you can plant centaurea in Scottsdale 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. You can get started a couple of weeks earlier by starting your centaurea indoors.

Last Frost Date

The average date of last frost is February 15 in Scottsdale. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Scottsdale may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Scottsdale you get a frost after February 15 be ready to protect your centaurea if you have a late frost.

USDA Zone Info for Scottsdale

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 Scottsdale

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