One of the best tools that you have as gardeners to help us determine 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.

A common way of determining when you can plant rock cress is to check out the USDA zone info for Lynnwood.

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 very cold tolerant you can plant them earlier in the year than other frost tender plants.

The earliest that you can plant rock cress in Lynnwood 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 couple of weeks earlier by starting your rock cress indoors.

Last Frost Date

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

Since the USDA zone info for Lynnwood is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Lynnwood you get surprised by a frost after March 15 so always be ready to cover your rock cress if you have a late frost.

USDA Zone Info for Lynnwood

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 Lynnwood

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