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.

By referring to the USDA zone info for Ukiah it's a good idea to figure out when it's the best time 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.

You can plant primula much earlier in the year because they do well in cold.

The earliest that you can plant primula in Ukiah 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 really do well. You can get started a couple of weeks earlier by starting your primula indoors.

Last Frost Date

The average date of last frost is February 15 in Ukiah. You should expect an average low temperature of 20°F in the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ukiah and it will vary from year to year. Half of the time in Ukiah you get a frost after February 15 so be sure to be ready to protect your primula in the event of a surprise late frost.

USDA Zone Info for Ukiah

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 Ukiah

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