One of the best tools that you have as gardeners to help us figure out 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.

The earliest that you can plant rock cress in Rialto can be figured out by checking out the USDA zone info.

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 tend to make it in quite a bit of cold which tells us that you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant rock cress in Rialto 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. You probably don't want to wait any later than that or else your rock cress may not have a chance to really do well. You can get started a few weeks earlier by starting your rock cress indoors.

Last Frost Date

On average the last frost is on January 31 in Rialto. You should expect an average low temperature of 30°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Rialto and it can change quite a bit from year to year. Half of the time in Rialto last frost occurs after January 31 so be sure to be ready to protect your rock cress in the event of a surprise late frost.

USDA Zone Info for Rialto

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Rialto

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