One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to figure out when it's possible to plant centaurea by looking at the USDA zone info for Pittsburgh.

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 moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant centaurea in Pittsburgh 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. Starting your centaurea indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Pittsburgh the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Pittsburgh and it changes from year to year. Half of the time in Pittsburgh last frost occurs after April 15 so make sure that you are ready to cover your centaurea in the event of a late frost.

USDA Zone Info for Pittsburgh

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Pittsburgh

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