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.

By looking at the USDA zone info for Riverton it's possible to figure out when it's a good idea 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.

Centaurea can survive in some cold which tells us that you can plant them a little earlier in the year than more sensitive plants.

The earliest that you can plant centaurea in Riverton 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 grow to maturity. Starting your centaurea indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Riverton. You can expect an average low temperature of -25°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 Riverton and it will vary from year to year. Half of the time in Riverton it frosts late in the year after May 15 so always be ready to cover your centaurea if you have one of those late frosts.

USDA Zone Info for Riverton

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 Riverton

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