Hej Dennis, kul att träffas!
You are lucky, you climate suits the palms better than mine, that's why I have to protect them during winter from frosts and mildews. Have you planted some of you palms outdoors or you only plan to do it the next spring? We had few frosty days, now very pleasant warm weather. The only one problem is mice, because last year probably mice population eave and they search food now everywhere. Palmbed is closed very good with styrofoam shilds and I've put within some ultrasonic repeller but don't shure that it works now because of lack of the light (sun-power battery).
Have you read the palm theme on finnish gardeners KLOROFYLLI-foorumi?

Terve Antti!

I have only just started my palmgrowing by seeds ordered from exoticgarden.fi,and rarepalmseeds.com and i´ve germinated them in a miniature greenhouse.
As of today i have managed to grow a 6 specimens of varying trachycarpus, and i plan to put them outside in the spring (in pots), to harden them...

In a couple of years time i think they will be ready to plant outdoors :-)

Although i have a fairly good climate, i think i have to cover with geotextile and ground insulation to prevent ground freeze...
the main advantage is that here, we rarely have temperatures below -15 degrees witch allows for covering only and no extra heating. Normally our winter temps ara around zero. That is much because nowadays we dont have any sea ice!

The main concern for me will be mice (like you) and ground rot due to much winter rain, so i will plant them in an high situated planting bed.

I am very excited that you try growing in your part of the country, and i am looking forward to read about your results :-)
I am greatful for tips on covering...

I havent read the klorofylli-forum since i dont understand finnish very good, but i´ll try and give it a shot.

Best of wishes /Dennis