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.

By using the USDA zone info for Moorhead it's a good idea to estimate when to plant purple rock cress.

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 earlier in the year than other plants that might not handle the cold.

The earliest that you can plant purple rock cress in Moorhead 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. 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

On average the last frost is on May 15 in Moorhead. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Moorhead is just an average the actual date of last frost will vary from year to year. Since half of the time in Moorhead 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 Moorhead

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Moorhead

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