I've owned a "Dixie" for 4 years now. It stands in a large pot and has produced 10-12 beautiful even fronds each year, except this year they have all grown out of a very tight area in the centre of the bark and so the central core is very narrow. Indeed it all seems tightly packed and the fronds have not unfurled as much as previous years. I didn't do anything differently over the last winter. Apart from the first winter when I cut the old fronds off before wrapping the trunk in an insulating jacket and stuffing straw down the core, the last 2 winters I left the old fronds and cut them off in the spring. So my concern is the new growth seems to be shooting from a narrowing space. Am I right to be concerned and if so what should I do about it. ?