Before planting it is a good idea to find your USDA Zone info to figure out 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.

You will be able to determine when it's the best time to plant purple rock cress by referring to the USDA zone info for Zone 7b.

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.

You can plant purple rock cress a lot earlier in the year because they do well in cold.

The earliest that you can plant purple rock cress in Zone 7b 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. Any later than that and your purple rock cress may not have a chance to fully mature. If you are starting your purple rock cress indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Zone 7b the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Zone 7b is just an average the actual date of last frost is different every year. Half of the time in Zone 7b last frost occurs after April 15 so make sure that you are ready to protect your purple rock cress in the event of a late frost.

USDA Zone Info for Zone 7b

Here is the info for USDA Zone 7b.

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

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

Plants to Grow in Zone 7b

You may be interested in your other planting guides for Zone 7b.