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.

One way of figuring out when you can plant purple rock cress is to refer to the USDA zone info for Stewartville.

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 earlier in the year because they do well in cold.

The earliest that you can plant purple rock cress in Stewartville 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. Starting your purple rock cress indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Stewartville the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Remember that USDA zone info for Stewartville is not always accurate and the actual date of last frost is different every year. Half of the time in Stewartville you get a frost after May 15 so always be ready to cover your purple rock cress if you have one of those late frosts.

USDA Zone Info for Stewartville

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 Stewartville

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