Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Normal can be reffered to in order to determine when it's the best time 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.

Since centaurea are moderately cold tolerant you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant centaurea in Normal 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. You can get started a few weeks earlier by starting your centaurea indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Normal may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Normal you get surprised by a frost after April 15 so always be ready to cover your centaurea if you have a surprise late frost.

USDA Zone Info for Normal

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 Normal

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