One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

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

Planting Calendar for Rock Cress

Frost tolerance for rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since rock cress are one of those plants that can tolerate quite a bit of cold weather you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant rock cress in Marana 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 rock cress and expect a good harvest is probably October. If you wait any later than that and your rock cress may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your rock cress indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Marana. In the coldest months of winter you should expect an average low temperature of 20°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Marana and it will vary from year to year. Half of the time in Marana you get a frost after February 15 so always be ready to protect your rock cress if you have a late frost.

USDA Zone Info for Marana

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Marana

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