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.

The first chance to plant primula in Sierra Madre should be determined by using 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.

Since primula do well in cold you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant primula in Sierra Madre 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. You probably don't want to wait any later than that or else your primula may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your primula indoors.

Last Frost Date

In Sierra Madre the average date of last frost happens on January 31. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for Sierra Madre is not always accurate the actual date of last frost is different every year. Half of the time in Sierra Madre last frost occurs after January 31 so just be sure to be ready to protect your primula if you have a surprise late frost.

USDA Zone Info for Sierra Madre

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 Sierra Madre

You may be interested in your other planting guides for Sierra Madre.