The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 rock cress in San Marino can be figured out by looking at the USDA zone info.

Planting Calendar for Rock Cress

Frost tolerance for rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Rock Cress do well in quite a bit of cold which means that you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant rock cress in San Marino 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 rock cress and expect a good harvest is probably October. You probably don't want to wait any later than that or else your rock cress may not have a chance to fully mature. Starting your rock cress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in San Marino. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for San Marino is just an average the actual date of last frost changes from year to year. Half of the time in San Marino last frost occurs after January 31 so make sure that you are ready to cover your rock cress in the event of a surprise late frost.

USDA Zone Info for San Marino

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 Marino

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