You shouldn't need to provide any protection for an acer. We grow in the garden in Scotland with no protection at all.

like the new avatar bulbaholic. didnt recognise you at first.
my acer doesnt get any special treatment either and it is in a big pot nfront of the house.

I got 2 different Acers about the same size at the same time, one went in a pot the other in the ground. Sadly i lost the one in the pot after a heavy snowfall. I would suggest at least wrapping the pot up in fleece if its a yound small plant.

young^^^

Even if the acer is in a pot it should survive the winter fine they do in our garden - what killed one of ours off was the 2 weeks of red hot weather in summer when we didn't water enough!

Very young A. palmatum trees can be damaged by (very severe) frost. If it's in a container, you can just shove it up into a hedge to give it some protection. I would think waterlogging would be the greater problem tho.

The biggest killer of Jap maples, is lack of moisture at the roots, which is more likely in a container grown plant