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 using the USDA zone info for Redlands you should be able to estimate when it's possible 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 means that you can get them planted much earlier than other frost tender plants.

The earliest that you can plant primula in Redlands 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 the last frost is on February 15 in Redlands. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Redlands is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Redlands you get a frost after February 15 so make sure that you are prepared to cover your primula in the event of a surprise late frost.

USDA Zone Info for Redlands

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 Redlands

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