Most of my fruit trees are 30 years old and it was only a few years ago that I realized that I've been pruning them poorly for all those years. The revelation came when I read Alan Haigh's essay on pruning that clearly delineated the underlying principles of orchard maintenance as a constant process of renewal and replacement of old wood with new wood. It does seem a little disconcerting to be reaching for the chain saw as I head out to prune my trees but that's where I'm at.