tree ferns

It depends where you are in the country I guess. In the SouthEast its not that cold for prolonged periods. 10 years ago I had a nice DS and it perished due to bad advice about packing with straw to protect from cold. I wasn't the tropical nut then that I am now.:D Basically it dried out and died. Fortunately it sucked like mad and I now have 8 little DS's one of which is already 6 inches of trunk.

During the winter I simply lay over leaves from my larger DA's and make sure they get a hosing every now and again if the winter weather has been dry. They certainly don't get packed and some years I just let the leaf fall linger around their crowns instead.

All comes down to knowing your garden and how it behaves in the winter