One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Sammamish you can figure out when you can plant echinacea by referring to the USDA zone info.

Planting Calendar for Echinacea

Frost tolerance for echinacea:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant echinacea slightly earlier in the year because they are barely cold tolerant.

The earliest that you can plant echinacea in Sammamish is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant echinacea and expect a good harvest is probably August. If you wait any later than that and your echinacea may not have a chance to really do well. You can get started a couple of weeks earlier by starting your echinacea indoors.

Last Frost Date

On average the last frost 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 may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Sammamish it frosts late in the year after March 15 so make sure that you are prepared to cover your echinacea if you have a 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.