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.

One way of figuring out when to plant centaurea is to check out the USDA zone info for Tualatin.

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 little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant centaurea in Tualatin 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 fully mature. You can get started a couple of weeks earlier by starting your centaurea indoors.

Last Frost Date

The average date of last frost is March 15 in Tualatin. In the coldest months of winter you should expect an average low temperature of 15°F.

Keep in mind that USDA zone info for Tualatin is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Tualatin you get a frost after March 15 be ready to cover your centaurea in the event of one of those late frosts.

USDA Zone Info for Tualatin

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Tualatin

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