The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for San Diego you will be able to estimate when it's a good idea 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.

Primula tend to make it in quite a bit of cold which means that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant primula in San Diego 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. If you wait any later than that and your primula may not have a chance to fully mature. Starting your primula indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In San Diego the average date of last frost happens on February 15. You can expect an average low temperature of 20°F in the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Diego and it changes from year to year. Half of the time in San Diego you get a frost after February 15 so just be sure to be ready to protect your primula in the event of a surprise late frost.

USDA Zone Info for San Diego

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in San Diego

You may be interested in your other planting guides for San Diego.