Where to grow?

Hello Ibc!
After a tiresome week, and a couple of hard blows, I actually found a new positiveness I didnt think would come.
Im pretty sure I lost several trees to this winter, but I dont want that to end my bonsai journey.
As you all know, Norway is a cold place. So I HAVE to go for native trees, to get the most out of them.
Im planning in the summer now to get a greenhouse. So I can put my natives it in when autumn comes.
But what trees should I get? Specialize on oaks? I lost a few of those too.
I get weather from sunny days with snow melting, to cold nights at -25c and wind.

What would you recommend as being tough trees for my winters?
I dont have access as far as I know to all those super growing mediums. And I dont have a wallet for it.
Ive used a cat litter only up to this day, and this kind doesnt break down. The tree that seemed to have the hardest cold was my picea
which was frozen solid, but that one is thriving atm. Due to work etc, I cant go around packing up every tree I have when winter and summer comes.
And I dont think anyone else up north in the world does this with their bonsai trees, not mentioning over hundreds of trees.
So, Im heading back to basics, and if anyone can help me, it would be much appriciated. The days of greenhouse bonsais are over.

Sincerely
Storm

Storm wrote:Hello Ibc!

I get weather from sunny days

Sincerely
Storm

Ha!
My bulldog "gets weather" from just about EVERYTHING!!!

In all seriousness; pines, Pines, PINES!!! They're hardy on benches, tolerates all the extreme weather we're used to in scandinavia, and they grow everywhere!

Pines obviously, and if you find your a busy guy and cant take on a bunch of trees, just keep one or two, maybe three. A finished tree, an 'in the process' tree, and one thats miles from completion. That way you always have work to do and yet aren't overwhelmed by your trees. Better to do a few things well than a bunch of things poorly. Its easy to have to many...FAR too easy.