One of the first steps you take when you are estimating 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.

By using the USDA zone info for Washougal you will be able to estimate when it's possible to plant yarrow.

Planting Calendar for Yarrow

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

Yarrow do ok in cold weather which means that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Washougal 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 grow to maturity. You can get started a little bit earlier by starting your yarrow indoors.

Last Frost Date

In Washougal the average date of last frost happens on March 15. You should expect an average low temperature of 15°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Washougal and it changes from year to year. Since half of the time in Washougal it frosts late in the year after March 15 be ready to protect your yarrow if you have a surprise late frost.

USDA Zone Info for Washougal

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 Washougal

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