How do i protect Dicksonia Antarctica in winter?

To protect a tree fern in winter we take a handful of straw and place it into the centre of the Tree Fern at the top (the crown). When you pack the straw be careful not to damage the any new fronds.

Tie the fronds up over the straw. More oftern than not this is enough protection. You can also add fleece or hessian around the tree, focusing on the crown area.