One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

By checking out the USDA zone info for Mill Valley you will be able to estimate when it's a good idea to plant rock cress.

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 do well in cold.

The earliest that you can plant rock cress in Mill 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 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 Mill Valley. It might get as low as 30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Mill Valley may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Mill Valley it frosts late in the year after January 31 be ready to cover your rock cress in the event of a late frost.

USDA Zone Info for Mill Valley

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 Mill Valley

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