The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when to plant centaurea is to look at the USDA zone info for Lewiston.

Planting Calendar for Centaurea

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

Centaurea tend to make it in mild cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant centaurea in Lewiston 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 couple of weeks earlier by starting your centaurea indoors.

Last Frost Date

On average the last frost is on April 15 in Lewiston. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Lewiston is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Lewiston you get a frost after April 15 be ready to protect your centaurea if you have a surprise late frost.

USDA Zone Info for Lewiston

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Lewiston

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