The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Salem you can figure out when it's a good idea to plant purple rock cress by reviewing 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.

Since purple rock cress do well in cold you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant purple rock cress in Salem 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 purple rock cress and expect a good harvest is probably September. You probably don't want to wait any later than that or else your purple rock cress may not have a chance to really do well. Starting your purple rock cress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Salem. You can expect an average low temperature of 5°F in the coldest months of winter.

Keep in mind that USDA zone info for Salem may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Salem there is a last frost after April 15 so make sure that you are prepared to cover your purple rock cress in the event of a surprise late frost.

USDA Zone Info for Salem

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Salem

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