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.

By checking out the USDA zone info for Mesa it's possible to determine when it's the best time to plant primula.

Planting Calendar for Primula

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

Since primula are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant primula in Mesa 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 primula and expect a good harvest is probably October. Any later than that and your primula may not have a chance to fully mature. If you are starting your primula indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Mesa may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Mesa you get a frost after February 15 be ready to cover your primula in the event of a surprise late frost.

USDA Zone Info for Mesa

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 Mesa

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