Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 figure out when you can plant centaurea by using the USDA zone info for Waterville.

Planting Calendar for Centaurea

Frost tolerance for centaurea:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Centaurea are moderately cold tolerant which tells us that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant centaurea in Waterville 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 really do well. You can get started a couple of weeks earlier by starting your centaurea indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Waterville and it will vary from year to year. Since half of the time in Waterville last frost occurs after April 15 be ready to protect your centaurea if you have a late frost.

USDA Zone Info for Waterville

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 Waterville

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