One of the best tools that you have as gardeners to help us figure out 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 determining when it's the best time to plant rock cress is to check out the USDA zone info for Vernal.

Planting Calendar for Rock Cress

Frost tolerance for rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since rock cress are very cold tolerant you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant rock cress in Vernal 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 rock cress and expect a good harvest is probably September. Any later than that and your rock cress may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your rock cress indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Vernal. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Vernal is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Vernal you get surprised by a frost after April 15 be ready to cover your rock cress in the event of a surprise late frost.

USDA Zone Info for Vernal

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Vernal

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