One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Sammamish should be reffered to in order to estimate when it's the best time to plant coreopsis.

Planting Calendar for Coreopsis

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

Coreopsis can survive in moderate cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant coreopsis 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 coreopsis and expect a good harvest is probably September. You probably don't want to wait any later than that or else your coreopsis may not have a chance to really do well. You can get started a few weeks earlier by starting your coreopsis indoors.

Last Frost Date

In Sammamish the average date of last frost happens on March 15. It might get as low as 15°F during the coldest months of winter.

It's important to remember that USDA zone info for Sammamish is an average and the actual date of last frost changes from year to year. Since half of the time in Sammamish you get a frost after March 15 be ready to protect your coreopsis in the event of one of those late frosts.

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.