One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when you can plant centaurea by using the USDA zone info for Preston.

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 tells us that you can get them planted earlier than other frost tender plants.

The earliest that you can plant centaurea in Preston 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 grow to maturity. Starting your centaurea indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Preston is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Preston last frost occurs after April 15 so always be ready to cover your centaurea if you have one of those late frosts.

USDA Zone Info for Preston

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Preston

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