Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's a good idea to plant purple rock cress by looking at the USDA zone info for Austin.

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 one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant purple rock cress in Austin is March. However, you really should wait until April 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 August. 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. 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 May 15 in Austin. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Austin is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Austin last frost occurs after May 15 be ready to cover your purple rock cress in the event of one of those late frosts.

USDA Zone Info for Austin

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Austin

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