Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant centaurea in Waterloo can be estimated 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.

Centaurea are one of those plants that can tolerate a little bit of cold weather which means that you can plant them earlier than plants that are more sensitive to the cold.

The earliest that you can plant centaurea in Waterloo 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 fully mature. If you are starting your centaurea indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Waterloo. You can expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Waterloo is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Waterloo there is a last frost after April 15 so make sure that you are ready to cover your centaurea if you have one of those late frosts.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Waterloo

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