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.

It's possible to figure out when to plant achillea by referring to the USDA zone info for Phoenix.

Planting Calendar for Achillea

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

Since achillea are very cold tolerant you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant achillea in Phoenix is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant achillea and expect a good harvest is probably September. Any later than that and your achillea may not have a chance to really do well. 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 March 15 in Phoenix. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Phoenix is an average and the actual date of last frost changes from year to year. Half of the time in Phoenix you get surprised by a frost after March 15 so make sure that you are ready to protect your achillea in the event of a surprise late frost.

USDA Zone Info for Phoenix

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Phoenix

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