Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when to plant purple rock cress is to refer to the USDA zone info for Zone 6a.

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 more sensitive plants.

The earliest that you can plant purple rock cress in Zone 6a is February. However, you really should wait until March 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 September. If you wait any later than that and your purple rock cress may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your purple rock cress indoors.

Last Frost Date

In Zone 6a the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Zone 6a is not always accurate the actual date of last frost changes from year to year. Since half of the time in Zone 6a last frost occurs after April 15 be ready to protect your purple rock cress if you have a late frost.

USDA Zone Info for Zone 6a

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Zone 6a

You may be interested in your other planting guides for Zone 6a.