The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Walnut Creek it's a good idea to figure out when you can plant sorrel.

Planting Calendar for Sorrel

Frost tolerance for sorrel:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since sorrel are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant sorrel in Walnut Creek 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 sorrel and expect a good harvest is probably October. If you wait any later than that and your sorrel may not have a chance to fully mature. If you are starting your sorrel indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Walnut Creek. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Walnut Creek may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Walnut Creek you get surprised by a frost after February 15 so be sure to be ready to cover your sorrel in the event of a late frost.

USDA Zone Info for Walnut Creek

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 Walnut Creek

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