Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when it's a good idea to plant yarrow in Sunnyvale by checking out 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.

Since yarrow are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Sunnyvale 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. If you wait any later than that and your yarrow may not have a chance to grow to maturity. Starting your yarrow indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Sunnyvale. It might get as low as 25°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Sunnyvale and it changes from year to year. Since half of the time in Sunnyvale there is a last frost after February 15 be ready to protect your yarrow in the event of a surprise late frost.

USDA Zone Info for Sunnyvale

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 Sunnyvale

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