I'm trying to gain an understanding of how double-leader trees structurally support themselves. Is one leader structurally dependend on the other both above and below ground? If one leader breaks above the juncture of the two, is the structural integrity of the other leader compromised, creating a potential hazard? I'd appreciate any literature recommendations or experience anyone can share. Thanks in advance.

Tom Watson

Reply to post by Tom Watson, on July 25, 2000 at 15:32:28:

Tom, IMO each case is different. My understanding is that there is also a difference between branch collar union and co-dominant leader attachments. It may be that breakout of one leader will result in greater or more rapid decay into trunk wood than might occur in the shedding of a branch the same size having a branch collar with no bark inclusion. It may also be that the loss of one leader will result in changes to the way the remaining leader responds to wind forces. Often I find that co-dominance has resulted in included bark and decay, and that is often made apparent when one branch has broken out. As a trend, I'd guess the odds are against most co-dominant unions having the strength of a single part of the same size, or of branch unions with discernable branch collars. This begs the question of what to do about it. Sorry, no literature comes to mind at the moment.