A couple of years ago I was determined to get some sugar maple staves in my stash. After cutting about a dozen or so of them down I gave up. Every tree I cut had a hollowed out, rotten core. It was very surprising to me as these were not big trees that I was cutting but most were around 6" diameter or so. These maples only grow in the mountains around here and are surrounded by mostly oaks and hickories, not sure if the trees being crowded has anything to do with it or not.