The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's a good idea to plant primula in Phoenix by looking at the USDA zone info.

Planting Calendar for Primula

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

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

The earliest that you can plant primula 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 primula and expect a good harvest is probably September. Any later than that and your primula may not have a chance to fully mature. You can get started a few weeks earlier by starting your primula indoors.

Last Frost Date

On average the last frost has passed is on March 15 in Phoenix. In the coldest months of winter you should expect an average low temperature of 10°F.

Keep in mind that USDA zone info for Phoenix may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Phoenix you get surprised by a frost after March 15 so always be ready to cover your primula in the event of one of those late frosts.

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.