One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Snoqualmie you will be able to estimate when it's the best time to plant rock cress.

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 do well in cold you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant rock cress in Snoqualmie 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. Any later than that and your rock cress may not have a chance to grow to maturity. Starting your rock cress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Snoqualmie. In the coldest months of winter you can expect an average low temperature of 15°F.

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 Snoqualmie and it can change quite a bit from year to year. Since half of the time in Snoqualmie last frost occurs after March 15 be ready to protect your rock cress if you have one of those late frosts.

USDA Zone Info for Snoqualmie

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 Snoqualmie

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