Chamaerops humilis/Siver Fan Palm
Please can anyone help me to identify the problem wth my Chamaerops humilis or Silver Fan Palm/ It's about 2 metres tall and has been outside in a border for about 10 years. Each new leaf is shiny and green and then gradually develops small brown/rust coloured marks that gradually take over the entire leaf, it becomes very unsightly. It's on a water drip feed and I compost it very year. Any ideas on how to stop this?