One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

The first chance to plant centaurea in Pullman can be determined by reviewing the USDA zone info.

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 means that you can plant them a little bit earlier than other frost tender plants.

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

The last month that you can plant centaurea and expect a good harvest is probably September. Any later than that and your centaurea may not have a chance to really do well. You can get started a little bit earlier by starting your centaurea indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Pullman. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Pullman is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Pullman you get a frost after April 15 so always be ready to cover your centaurea in the event of one of those late frosts.

USDA Zone Info for Pullman

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Pullman

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