The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when to plant achillea by looking at the USDA zone info for Washington.

Planting Calendar for Achillea

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

Achillea are very cold tolerant which means that you can get them planted much earlier than other plants that might not handle the cold.

The earliest that you can plant achillea in Washington 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. If you wait any later than that and your achillea may not have a chance to fully mature. You can get started a little bit earlier by starting your achillea indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Washington. It might get as low as 10°F during the coldest months of winter.

Keep in mind that USDA zone info for Washington is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Washington last frost occurs after March 15 so make sure that you are prepared to protect your achillea if you have a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Washington

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