Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of making a decision about when it's a good idea to plant purple rock cress is to consult the USDA zone info for Vandalia.

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.

You can plant purple rock cress much earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant purple rock cress in Vandalia 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. Any later than that and your purple rock cress may not have a chance to fully mature. Starting your purple rock cress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Vandalia. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Vandalia 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 Vandalia 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 Vandalia

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Vandalia

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