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.

You will be able to figure out when it's the best time to plant achillea by looking at the USDA zone info for Patterson.

Planting Calendar for Achillea

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

Achillea do well in pretty solid cold which means that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Patterson 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 grow to maturity. You can get started a little bit earlier by starting your achillea indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Patterson. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Patterson may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Patterson it frosts late in the year after February 15 so make sure that you are prepared to cover your achillea in the event of one of those late frosts.

USDA Zone Info for Patterson

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 Patterson

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