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.

A common way of getting a good idea when to plant centaurea is to check out the USDA zone info for Hillsboro.

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 one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant centaurea in Hillsboro 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 fully mature. You can get started a little bit earlier by starting your centaurea indoors.

Last Frost Date

The average date of last frost is March 15 in Hillsboro. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Hillsboro is an average the actual date of last frost changes from year to year. Half of the time in Hillsboro it frosts late in the year after March 15 so be sure to be ready to cover your centaurea if you have one of those late frosts.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Hillsboro

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