The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant achillea in Palo Alto should be figured out by checking out the USDA zone info.

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 quite a bit earlier in the year because they do well in cold.

The earliest that you can plant achillea in Palo Alto 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. If you wait any later than that and your achillea may not have a chance to fully mature. If you are starting your achillea indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Palo Alto the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Palo Alto is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Palo Alto you get surprised by a frost after February 15 be ready to protect your achillea if you have a late frost.

USDA Zone Info for Palo Alto

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 Palo Alto

You may be interested in your other planting guides for Palo Alto.