When to Plant Rock Cress in Mount Vernon, WA

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.

By checking out the USDA zone info for Mount Vernon it's a good idea to estimate when you can 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.

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

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant rock cress
Possibly ok, but a risky time to plant rock cress
Probably not a good time to plant rock cress

The earliest that you can plant rock cress in Mount Vernon 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 really do well. If you are starting your rock cress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Mount Vernon. In the coldest months of winter you should expect an average low temperature of 10°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Mount Vernon and it changes from year to year. Half of the time in Mount Vernon last frost occurs after March 15 so make sure that you are prepared to cover your rock cress in the event of a late frost.

USDA Zone Info for Mount Vernon

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low10°F
Highest Expected Low15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Mount Vernon

You may be interested in your other planting guides for Mount Vernon.