One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when to plant yarrow by checking out the USDA zone info for La Mesa.

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 very cold tolerant you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in La Mesa 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 La Mesa the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Remember that USDA zone info for La Mesa is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in La Mesa you get surprised by a frost after January 31 so always be ready to protect your yarrow in the event of a surprise late frost.

USDA Zone Info for La Mesa

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 La Mesa

You may be interested in your other planting guides for La Mesa.