Tree planting

I have a rowan tree sapling in a pot (I think it was a freebee a couple of years ago from Andrex!), about two and a half feet high, which has now lost all its leaves.  Would this be a good time to plant it in the ground or should I leave it until the Spring?  We are in the North of Scotland on a hill with a very exposed garden, and the forecast is for Arctic winds at the weekend .

I think now would be the perfect time to plant it   Have you got a well-drained spot ready?  Remember rowans don't like soggy bottoms, so if you're digging out a hole dig a big one and put some grit or similar in the bottom to make sure it doesn't turn into a sump and hold water around the roots.  Otherwise I'm sure it'll be fine.  

Now that it's lost it's leaves it'll cope with winter winds (even your winter winds) absolutely fine and as it's only little it shouldn't need staking.  It'll be perfectly at home on a Scottish hillside 

Planting should be done now or in the spring-the only caveat is not when the ground is frozen.

OK.  Thank you both very much.  I'll get some grit to put in the hole and will hopefully get it into the ground if the weather permits this weekend.  I have another couple of rowans elsewhere in the garden (proper garden centre sized ones!) and they seem to be doing OK in the clay.