The USDA Zone info is a great tool for gardeners to help us figure out 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.

You can estimate when to plant rock cress in Sonora by reviewing 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 tend to make it in a bit of cold which means that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant rock cress in Sonora 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. You can get started a little bit earlier by starting your rock cress indoors.

Last Frost Date

On average the last frost is on February 15 in Sonora. It might get as low as 20°F during the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Sonora and it will vary from year to year. Since half of the time in Sonora last frost occurs after February 15 be ready to cover your rock cress in the event of one of those late frosts.

USDA Zone Info for Sonora

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Sonora

You may be interested in your other planting guides for Sonora.