One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when it's the best time to plant purple rock cress in Williamsburg by checking out 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 are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them much earlier than other frost tender plants.

The earliest that you can plant purple rock cress in Williamsburg 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. If you wait any later than that and your purple rock cress may not have a chance to really do well. If you are starting your purple rock cress indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Williamsburg. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Williamsburg is just an average the actual date of last frost changes from year to year. Half of the time in Williamsburg you get surprised by a frost after April 15 so be sure to be ready to protect your purple rock cress if you have one of those late frosts.

USDA Zone Info for Williamsburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Williamsburg

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