Hello Rita -
I too live up in Seattle and cover my plants in winter - based on weather - this year it was mid Nov. when I covered them.
Since your plantings are new, I'd cover them - especially if this is easy for you to do.
For me all my new plants seem more vulnerable to the rains than the established plantings
I noticed you and your brother signed up for the clinic! Meet in person there
Expect to be blown away the first time you visit Kevin's and Lynn's yards = so many semps!
Good luck with your plants!