Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Oregon you can figure out when you can plant centaurea by using 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 start planting them earlier than other frost tender plants.

The earliest that you can plant centaurea in Oregon 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 grow to maturity. You can get started a little bit earlier by starting your centaurea indoors.

Last Frost Date

In Oregon the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

It's important to remember that USDA zone info for Oregon may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Oregon there is a last frost after April 15 so make sure that you are ready to protect your centaurea in the event of a surprise late frost.

USDA Zone Info for Oregon

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oregon

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