One of the first steps you take when you are figuring out 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.

A common way of estimating when it's a good idea to plant purple rock cress is to check out the USDA zone info for Rio Grande City.

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 are very cold tolerant you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant purple rock cress in Rio Grande City is January. However, you really should wait until February 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 October. Any later than that and your purple rock cress may not have a chance to fully mature. You can get started a few weeks earlier by starting your purple rock cress indoors.

Last Frost Date

In Rio Grande City the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Always keep in mind that USDA zone info for Rio Grande City may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Rio Grande City there is a last frost after February 15 so always be ready to cover your purple rock cress in the event of one of those late frosts.

USDA Zone Info for Rio Grande City

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Rio Grande City

You may be interested in your other planting guides for Rio Grande City.