Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Sonoma you can determine when you can plant yarrow by looking at the USDA zone info.

Planting Calendar for Yarrow

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

Yarrow do well in quite a bit of cold which tells us that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant yarrow in Sonoma is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant yarrow and expect a good harvest is probably October. Any later than that and your yarrow may not have a chance to grow to maturity. If you are starting your yarrow indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Sonoma the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Sonoma is an average the actual date of last frost will vary from year to year. Half of the time in Sonoma you get a frost after February 15 so make sure that you are ready to protect your yarrow in the event of a late frost.

USDA Zone Info for Sonoma

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Sonoma

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