Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant centaurea in Gresham should be estimated 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 tend to make it in a little bit of cold which means that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant centaurea in Gresham 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 fully mature. If you are starting your centaurea indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Gresham the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 15°F.

Always keep in mind that USDA zone info for Gresham may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Gresham you get surprised by a frost after March 15 be ready to protect your centaurea in the event of a surprise late frost.

USDA Zone Info for Gresham

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 Gresham

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