One of the first steps you take when you are getting a good idea 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.

You should be able to estimate when it's possible to plant purple rock cress by referring to the USDA zone info for Alma.

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 a lot earlier in the year than more sensitive plants.

The earliest that you can plant purple rock cress in Alma 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

In Alma the average date of last frost happens on April 15. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Alma is an average the actual date of last frost changes from year to year. Since half of the time in Alma you get a frost after April 15 be ready to cover your purple rock cress if you have a surprise late frost.

USDA Zone Info for Alma

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 Alma

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