Before planting it is a good idea to find your USDA Zone info to estimate 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.

A common way of getting a good idea when to plant yarrow is to check out the USDA zone info for San Marcos.

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 tells us that you can plant them a quite a bit earlier than other frost tender plants.

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

Last Frost Date

In San Marcos the average date of last frost happens on January 31. You should expect an average low temperature of 30°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Marcos and it changes from year to year. Half of the time in San Marcos it frosts late in the year after January 31 so always be ready to cover your yarrow in the event of one of those late frosts.

USDA Zone Info for San Marcos

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 Marcos

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