The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant yarrow by referring to the USDA zone info for Pacific.

Planting Calendar for Yarrow

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

Yarrow are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than other frost tender plants.

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

Last Frost Date

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

Since the USDA zone info for Pacific may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Pacific you get surprised by a frost after April 15 so just be sure to be ready to cover your yarrow in the event of a surprise late frost.

USDA Zone Info for Pacific

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Pacific

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