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.

A common way of getting a good idea when it's the best time to plant centaurea is to examine the USDA zone info for Richmond.

Planting Calendar for Centaurea

Frost tolerance for centaurea:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since centaurea do well in moderate cold you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant centaurea in Richmond 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. If you are starting your centaurea indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Richmond is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Richmond you get surprised by a frost after April 15 so be sure to be ready to cover your centaurea if you have a late frost.

USDA Zone Info for Richmond

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 Richmond

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