One of the first steps you take when you are figuring out your gardening schedule is find your 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 first opportunity to plant primula in Grass Valley can be determined by checking out 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 are very cold tolerant you can plant them a lot earlier in the year than other frost tender plants.

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

Last Frost Date

The average date of last frost is February 15 in Grass Valley. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Grass Valley is an average the actual date of last frost will vary from year to year. Since half of the time in Grass Valley last frost occurs after February 15 be ready to protect your primula in the event of a late frost.

USDA Zone Info for Grass Valley

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 Grass Valley

You may be interested in your other planting guides for Grass Valley.