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 reviewing the USDA zone info for Hilliard.

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 Hilliard 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 few weeks earlier by starting your centaurea indoors.

Last Frost Date

The average date of last frost is April 15 in Hilliard. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Hilliard is an average the actual date of last frost is different every year. Half of the time in Hilliard it frosts late in the year after April 15 so always be ready to cover your centaurea in the event of one of those late frosts.

USDA Zone Info for Hilliard

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Hilliard

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