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.

In Alpena you can estimate when to plant centaurea by looking at the USDA zone info.

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 little bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant centaurea in Alpena 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. If you wait any later than that and your centaurea may not have a chance to grow to maturity. You can get started a little bit earlier by starting your centaurea indoors.

Last Frost Date

In Alpena the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Alpena and it is different every year. Since half of the time in Alpena last frost occurs after April 15 be ready to protect your centaurea in the event of a late frost.

USDA Zone Info for Alpena

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 Alpena

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