One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Gridley can be looked at to figure out when you can plant achillea.

Planting Calendar for Achillea

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

Achillea can survive in cold weather which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant achillea in Gridley 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 few weeks earlier by starting your achillea indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Gridley. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for Gridley is just an average and the actual date of last frost changes from year to year. Since half of the time in Gridley you get a frost after February 15 be ready to protect your achillea if you have one of those late frosts.

USDA Zone Info for Gridley

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 Gridley

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