Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Green River should be used to determine when to plant centaurea.

Planting Calendar for Centaurea

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

You can plant centaurea a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant centaurea in Green River 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 centaurea and expect a good harvest is probably August. You probably don't want to wait any later than that or else your centaurea may not have a chance to really do well. You can get started a few weeks earlier by starting your centaurea indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Green River. You can expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Green River is not always accurate the actual date of last frost will vary from year to year. Half of the time in Green River there is a last frost after May 15 so just be sure to be ready to cover your centaurea if you have one of those late frosts.

USDA Zone Info for Green River

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Green River

You may be interested in your other planting guides for Green River.