One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant purple rock cress in Ukiah can be estimated by referring to the USDA zone info.

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.

Since purple rock cress are very cold tolerant you can plant them a lot earlier in the year than more sensitive plants.

The earliest that you can plant purple rock cress in Ukiah 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. You probably don't want to wait any later than that or else your purple rock cress may not have a chance to really do well. If you are starting your purple rock cress indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Ukiah the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Ukiah and it can change quite a bit from year to year. Half of the time in Ukiah there is a last frost after February 15 so just be sure to be ready to protect your purple rock cress in the event of one of those late frosts.

USDA Zone Info for Ukiah

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 Ukiah

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