Before planting it is a good idea to find your USDA Zone info to figure out 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 making a decision about when you can plant achillea is to check out the USDA zone info for Calistoga.

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 are very cold tolerant.

The earliest that you can plant achillea in Calistoga 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. You probably don't want to wait any later than that or else your achillea may not have a chance to fully mature. Starting your achillea indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Calistoga. It might get as low as 20°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Calistoga may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Calistoga there is a last frost after February 15 be ready to protect your achillea if you have a surprise late frost.

USDA Zone Info for Calistoga

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 Calistoga

You may be interested in your other planting guides for Calistoga.