One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when to plant centaurea by using the USDA zone info for Rice Lake.

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 one of those plants that can tolerate a little bit of cold weather you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant centaurea in Rice Lake is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant centaurea and expect a good harvest is probably August. You probably don't want to wait any later than that or else 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

On average the last frost has passed is on May 15 in Rice Lake. You can expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Rice Lake is just an average the actual date of last frost will vary from year to year. Half of the time in Rice Lake it frosts late in the year after May 15 so just be sure to be ready to protect your centaurea if you have a surprise late frost.

USDA Zone Info for Rice Lake

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Rice Lake

You may be interested in your other planting guides for Rice Lake.