One of the first steps you take when you are getting a good idea 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.

You can figure out when it's a good idea to plant yarrow in Atherton 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.

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 plants that might not handle the cold.

The earliest that you can plant yarrow in Atherton 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 fully mature. 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 Atherton the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Atherton is an average and the actual date of last frost is different every year. Half of the time in Atherton you get surprised by a frost after February 15 so make sure that you are prepared to protect your yarrow in the event of a late frost.

USDA Zone Info for Atherton

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 Atherton

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