I posted this question in another conifer forum, and didn't get much response. I will try it here. I found that after about ten years or so, my Chamaecyparis pisifera 'Boulevard' or 'Snow' etc. seem to progressively lose more and more of the nice coloured leaves. Are they expected to be replaced every 10 years or so? Another related question is, after they lose much of their leaves, is there any hope of recovering, or should they be destroyed and new ones propagated?