One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 will be able to figure out when it's possible to plant rock cress by checking out the USDA zone info for Tempe.

Planting Calendar for Rock Cress

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

Rock Cress are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant rock cress in Tempe 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. Starting your rock cress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Tempe. You should expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for Tempe is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Tempe you get surprised by a frost after February 15 be ready to protect your rock cress in the event of a surprise late frost.

USDA Zone Info for Tempe

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 Tempe

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