The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's a good idea to plant purple rock cress is to consult the USDA zone info for Federal Way.

Planting Calendar for Purple Rock Cress

Frost tolerance for purple rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Purple Rock Cress are one of those plants that can tolerate quite a bit of cold weather which means that you can plant them a quite a bit earlier than other frost tender plants.

The earliest that you can plant purple rock cress in Federal Way 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 purple rock cress and expect a good harvest is probably September. Any later than that and your purple rock cress may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your purple rock cress indoors.

Last Frost Date

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

Since the USDA zone info for Federal Way is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Federal Way you get surprised by a frost after March 15 so make sure that you are ready to cover your purple rock cress in the event of a late frost.

USDA Zone Info for Federal Way

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 Federal Way

You may be interested in your other planting guides for Federal Way.