Well as I said its where I would have made the cut in the photo, Shigo certainly has it over me and I have read all his published works even the USFD papers, I'm not disputing that his knowledge and understanding is superior to mine it was and is. Just that in the case of co-dominant stems there is no branch protection zone, all you are trying to achieve is to encourage the effective closure of the wound, and limit the production of epicormics..look if the co-dominant is advanced enough with enough live foliage and demanding equal if not greater rights to Auxin and Gibberelin control it you'll get epicormics. My concern when removing co-dominants like the one in the photo is to balance two objectives, effective closure limiting the amount of dysfunction my cut produces and reducing epicormic growth as much as poss.
Shigo's instructions re co-dominants to hit the bottom mark extended from the bottom of the BBR across to the outer bark I understand perfectly, and don't dispute. His main point was to warn of the dangers of leaving a stub live (for a time) but without a defense system. I don't consider the difference between the red line and the blue line in the photo to be that great...red line less wood tissue left agreed, but more wood tissue surface area exposed to dysfunction, the impact of which on urban trees already experiencing multiple streeses should not be ignored. The blue line attempts to split hairs by lifting the bottom slightly to reduce that area.
It's just my opinion Ekka, its not me saying Shigo's wrong and I'm right, Shigo is right I just want to try to protect the tree more, if my tree biology is wrong here I'll take pointers please.
SF |