Some ferns are deciduous while others are evergreen (or semi-evergreen). If you've had this fern since before last winter, can you remember what it was like last autumn, Motherhen? Do you happen to know what its name is?

My deciduous ferns are looking awful, too, but I leave the dead leaves on them as a protection for the winter.

I too leave them all on as they make wonderful shelters for good insects and the birds go and dig 'em out when the get ultra hungry.....LOL Then I cut them all back in early Spring and the fresh unfurling fronds are such a delight to see as they un-curl !!!
If you prefer to be a tidy gardener - then you can cut back the fronds when they die down - but if it is in a pot - you might then need to put protection over the crown to stop the rot ...as the saying goes ....although most ferns are very hardy.

Thanks for your comments, my fern is a Dicksonia, sorry should have mentioned that. It lost some leaves last autumn but didn't look as bad as this.

OMG Motherhen - that is a tree fern isn't it! In which case I was way off beam.....and it WILL need protection over the winter and possibly taken indoors if it is in a pot - unless you wrap it well with Hessian and/or bubble wrap!
This site could give you a few pointers I think...but it sounds as though it has become a bit too dry at the roots over the seasons ....anyway have a look and hope it helps....
http://www.letsgogardening.co.uk/PD/Dicksonia_Antarctica.htm

Thanks Alzheimer, its now safely indoors for the winter months ,will check out the suggested site, thanks again .