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

The USDA zone info for San Diego can be looked at to figure out when it's the best time to plant achillea.

Planting Calendar for Achillea

Frost tolerance for achillea:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant achillea earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant achillea in San Diego 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 achillea and expect a good harvest is probably October. Any later than that and your achillea may not have a chance to really do well. Starting your achillea indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in San Diego. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for San Diego is just an average the actual date of last frost is different every year. Half of the time in San Diego you get surprised by a frost after February 15 so always be ready to cover your achillea in the event of one of those late frosts.

USDA Zone Info for San Diego

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in San Diego

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