The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant rock cress in Tualatin can be estimated by reviewing 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.

You can plant rock cress earlier in the year because they are very cold tolerant.

The earliest that you can plant rock cress in Tualatin 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 grow to maturity. You can get started a few weeks earlier by starting your rock cress indoors.

Last Frost Date

On average the last frost is on March 15 in Tualatin. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Tualatin is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Tualatin last frost occurs after March 15 be ready to protect your rock cress in the event of one of those late frosts.

USDA Zone Info for Tualatin

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 Tualatin

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