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 Beaverton should be determined by referring to 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 more sensitive plants.

The earliest that you can plant rock cress in Beaverton 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. If you wait any later than that and 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 little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Beaverton. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Beaverton is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Beaverton last frost occurs after March 15 so make sure that you are prepared to protect your rock cress in the event of a late frost.

USDA Zone Info for Beaverton

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Beaverton

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