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.

In Hillsboro you can figure out when you can plant rock cress by looking at 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.

Since rock cress are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant rock cress in Hillsboro 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 really do well. If you are starting your rock cress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Hillsboro. It might get as low as -10°F during the coldest months of winter.

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 Hillsboro and it changes from year to year. Half of the time in Hillsboro you get surprised by a frost after April 15 so always be ready to protect your rock cress in the event of a late frost.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 6a.

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

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Hillsboro

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