One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Cottage Grove should be reffered to in order to estimate when you can 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 are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than other frost tender plants.

The earliest that you can plant centaurea in Cottage Grove 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. Any later than that and your centaurea may not have a chance to grow to maturity. 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 Cottage Grove the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Cottage Grove is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Cottage Grove you get a frost 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 Cottage Grove

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Cottage Grove

You may be interested in your other planting guides for Cottage Grove.