One of the first steps you take when you are figuring out 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.

In Rifle you can determine when you can plant centaurea 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 are moderately cold tolerant which means that you can get them planted earlier than other frost tender plants.

The earliest that you can plant centaurea in Rifle 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. You probably don't want to wait any later than that or else your centaurea may not have a chance to really do well. Starting your centaurea indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Rifle. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rifle and it can change quite a bit from year to year. Half of the time in Rifle you get a frost after April 15 so just be sure to be ready to protect your centaurea in the event of one of those late frosts.

USDA Zone Info for Rifle

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Rifle

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