When to Plant Purple Rock Cress in Zone 3b

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Zone 3b you can figure out when it's a good idea to plant purple rock cress by referring to the USDA zone info.


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 cold which tells us that you can plant them a quite a bit earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant purple rock cress
Possibly ok, but a risky time to plant purple rock cress
Probably not a good time to plant purple rock cress

The earliest that you can plant purple rock cress in Zone 3b 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. You probably don't want to wait any later than that or else your purple rock cress may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your purple rock cress indoors.

Last Frost Date

In Zone 3b the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -35°F.

Since the USDA zone info for Zone 3b may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Zone 3b you get surprised by a frost after May 15 so make sure that you are ready to cover your purple rock cress if you have one of those late frosts.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-35°F
Highest Expected Low-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in your other planting guides for Zone 3b.