One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

The USDA zone info for Berkeley should be reviewed to determine 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 do well in cold which tells us that you can get them planted much earlier than other plants that might not handle the cold.

The earliest that you can plant primula in Berkeley 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 really do well. Starting your primula indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Berkeley. In the coldest months of winter you can expect an average low temperature of 30°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Berkeley and it changes from year to year. Since half of the time in Berkeley you get a frost after January 31 be ready to cover your primula in the event of a late frost.

USDA Zone Info for Berkeley

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Berkeley

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