One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

In Ellensburg you can estimate when it's possible to plant achillea by using the USDA zone info.

Planting Calendar for Achillea

Frost tolerance for achillea:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant achillea much earlier in the year because they are very cold tolerant.

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

Last Frost Date

In Ellensburg the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Keep in mind that USDA zone info for Ellensburg may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Ellensburg you get a frost after April 15 so make sure that you are prepared to cover your achillea in the event of one of those late frosts.

USDA Zone Info for Ellensburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Ellensburg

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