The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Prosser you can determine when to plant centaurea by looking at 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.

Since centaurea are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant centaurea in Prosser 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. If you wait any later than that and 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 Prosser. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Prosser is an average the actual date of last frost changes from year to year. Half of the time in Prosser there is a last frost after April 15 so make sure that you are prepared to cover your centaurea if you have a late frost.

USDA Zone Info for Prosser

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Prosser

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