One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 first opportunity to plant centaurea in Sammamish should be figured out by reviewing 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 do ok in moderate cold which tells us that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant centaurea in Sammamish 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. Starting your centaurea indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on March 15 in Sammamish. You should expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Sammamish is an average the actual date of last frost changes from year to year. Since half of the time in Sammamish last frost occurs after March 15 be ready to cover your centaurea in the event of a surprise late frost.

USDA Zone Info for Sammamish

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

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

Plants to Grow in Sammamish

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