One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Phoenix it's a good idea to estimate when it's possible to plant rosemary.

Planting Calendar for Rosemary

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

You can plant rosemary quite a bit earlier in the year because they do well in cold.

The earliest that you can plant rosemary in Phoenix 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 rosemary and expect a good harvest is probably October. You probably don't want to wait any later than that or else your rosemary may not have a chance to really do well. If you are starting your rosemary indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Phoenix the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Always keep in mind that USDA zone info for Phoenix is just an average and the actual date of last frost changes from year to year. Since half of the time in Phoenix you get surprised by a frost after February 15 be ready to protect your rosemary in the event of one of those late frosts.

USDA Zone Info for Phoenix

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 Phoenix

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