One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when it's the best time to plant sorrel by looking at the USDA zone info for San Mateo.

Planting Calendar for Sorrel

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

Sorrel do well in moderate cold which tells us that you can start planting them earlier than more sensitive plants.

The earliest that you can plant sorrel in San Mateo 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 grow to maturity. Starting your sorrel indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in San Mateo. It might get as low as 30°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Mateo and it is different every year. Half of the time in San Mateo last frost occurs after January 31 so just be sure to be ready to cover your sorrel in the event of a surprise late frost.

USDA Zone Info for San Mateo

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 San Mateo

You may be interested in your other planting guides for San Mateo.