One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's the best time to plant purple rock cress by referring to the USDA zone info for Huron.

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 well in a bit of cold which tells us that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant purple rock cress in Huron 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. 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 little bit earlier by starting your purple rock cress indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Huron is an average and the actual date of last frost is different every year. Half of the time in Huron you get surprised by a frost after May 15 so be sure to be ready to protect your purple rock cress in the event of a late frost.

USDA Zone Info for Huron

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 Huron

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