One of the best tools that you have as gardeners to help us figure out 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.

The USDA zone info for Presidio should be reviewed to figure out when you can plant purple rock cress.

Planting Calendar for Purple Rock Cress

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

Purple Rock Cress tend to make it in quite a bit of cold which means that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant purple rock cress in Presidio 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 purple rock cress and expect a good harvest is probably October. Any later than that and your purple rock cress may not have a chance to really do well. Starting your purple rock cress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Presidio. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Presidio is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Presidio you get a frost after February 15 so just be sure to be ready to cover your purple rock cress in the event of a surprise late frost.

USDA Zone Info for Presidio

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 Presidio

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