One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Belle Fourche can be used to estimate when it's the best time 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.

You can plant purple rock cress a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant purple rock cress in Belle Fourche 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 really do well. You can get started a couple of weeks earlier by starting your purple rock cress indoors.

Last Frost Date

In Belle Fourche the average date of last frost happens on May 15. You can expect an average low temperature of -25°F in the coldest months of winter.

Remember that USDA zone info for Belle Fourche is not always accurate and the actual date of last frost is different every year. Half of the time in Belle Fourche last frost occurs after May 15 so always be ready to cover your purple rock cress in the event of a surprise late frost.

USDA Zone Info for Belle Fourche

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 Belle Fourche

You may be interested in your other planting guides for Belle Fourche.