Before planting it is a good idea to find your USDA Zone info to determine 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.

By checking out the USDA zone info for Granite City it's possible to figure out when to plant centaurea.

Planting Calendar for Centaurea

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

You can plant centaurea a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant centaurea in Granite City 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. Starting your centaurea indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Granite City. You should expect an average low temperature of -5°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Granite City and it can change quite a bit from year to year. Since half of the time in Granite City you get surprised by a frost after April 15 be ready to cover your centaurea in the event of a late frost.

USDA Zone Info for Granite City

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 Granite City

You may be interested in your other planting guides for Granite City.