Before planting it is a good idea to find your USDA Zone info to determine 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 Ionia should be reviewed to determine 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.

Centaurea do well in moderate cold which tells us that you can plant them earlier than more sensitive plants.

The earliest that you can plant centaurea in Ionia 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 really do well. If you are starting your centaurea indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Ionia 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 Ionia is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Ionia you get surprised by a frost after April 15 be ready to cover your centaurea if you have a late frost.

USDA Zone Info for Ionia

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 Ionia

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