After bringing the tree ferns to Ireland 14 years ago they were eventually put into the ground. Wrapped them in wire and straw the first two years but old fronds went brown. Last year put them into fleece bags. One now has in excess of twenty fronds and the other in excess of thirty. There is no way I can get them into fleece bags this year does anyone please have any ideas on how to protect them. They look wonderful this year and are still unfurling fronds.