One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Umatilla should be read to determine when to plant rock cress.

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 means that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant rock cress in Umatilla 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 rock cress and expect a good harvest is probably September. You probably don't want to wait any later than that or else your rock cress may not have a chance to fully mature. If you are starting your rock cress indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Umatilla. It might get as low as 5°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Umatilla and it changes from year to year. Half of the time in Umatilla you get surprised by a frost after April 15 so make sure that you are ready to cover your rock cress if you have one of those late frosts.

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Umatilla

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