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.

A common way of determining when to plant purple rock cress is to examine the USDA zone info for Robstown.

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 do ok in cold weather which tells us that you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant purple rock cress in Robstown 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. You can get started a couple of weeks earlier by starting your purple rock cress indoors.

Last Frost Date

The average date of last frost is February 15 in Robstown. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Robstown may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Robstown there is a last frost after February 15 so always be ready to cover your purple rock cress in the event of a late frost.

USDA Zone Info for Robstown

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 Robstown

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