Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's the best time to plant primula by referring to the USDA zone info for Walnut.

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 start planting them much earlier than other frost tender plants.

The earliest that you can plant primula in Walnut 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. You can get started a little bit earlier by starting your primula indoors.

Last Frost Date

In Walnut the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

Keep in mind that USDA zone info for Walnut may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Walnut you get surprised by a frost after January 31 so make sure that you are prepared to protect your primula in the event of a late frost.

USDA Zone Info for Walnut

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 Walnut

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