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.

You can determine when it's possible to plant rock cress in San Ramon by referring to 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.

You can plant rock cress a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant rock cress in San Ramon 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. Any later than that and your rock cress may not have a chance to grow to maturity. Starting your rock cress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in San Ramon. It might get as low as 25°F during the coldest months of winter.

It's important to remember that USDA zone info for San Ramon is just an average and the actual date of last frost will vary from year to year. Since half of the time in San Ramon there is a last frost after February 15 be ready to cover your rock cress if you have one of those late frosts.

USDA Zone Info for San Ramon

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 San Ramon

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