One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when it's possible to plant yarrow by referring to the USDA zone info for San Rafael.

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 pretty solid cold which means that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant yarrow in San Rafael 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. Starting your yarrow indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in San Rafael. It might get as low as 30°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for San Rafael and it changes from year to year. Since half of the time in San Rafael you get surprised by a frost after January 31 be ready to protect your yarrow in the event of a late frost.

USDA Zone Info for San Rafael

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Rafael

You may be interested in your other planting guides for San Rafael.