The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when it's possible to plant purple rock cress is to consult the USDA zone info for Perris.

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 pretty solid cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant purple rock cress in Perris 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 grow to maturity. 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 Perris the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that USDA zone info for Perris is an average and the actual date of last frost changes from year to year. Half of the time in Perris 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 a surprise late frost.

USDA Zone Info for Perris

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 Perris

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