When can I plant Purple Rock Cress in Zone 3a

One of the first steps we take when we are estimating our gardening schedule is find our USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

The first opportunity to plant purple rock cress in Zone 3a can be determined by reviewing the USDA zone info.


Planting Calendar for Purple Rock Cress

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

Purple Rock Cress can survive in cold weather which tells us that you can plant them much earlier in the year than other plants that might not handle the cold.

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 3a 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 grow to maturity. Starting your purple rock cress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 3a. We should expect an average low temperature of -40°F in the coldest months of winter.

Always keep in mind that our actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 3a and it will vary from year to year. Since half of the time in Zone 3a it frosts late in the year after May 15 be ready to cover your purple rock cress in the event of a late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-40°F
Highest Expected Low-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in our other planting guides for Zone 3a.