I also laid the challenge down somewhere about the myth of heartwood not having defense capabilities ... so did Shigo.
It's common thought to say co-dominants have no branch protection zone, hey, there's just heartwood and that's the only defense so leaving more of it should do better????
I accept the rationale and logic of this. I also used to prune way shyer of the red line till say the last 7 years.
There's defense capabilities of heartwood, we need to find some facts on this but I can only find generalized statements and some diagrams showing whats called the barrier zone where the heartwood alters.... but no real scientific data.
Also, perhaps cutting to the red line will mean faster closure. On some species I noticed that cutting off the mark resulted in the bark dying back a bit and bit of a dead stub. Remember back in the old days they flush cut as closure was rapid. In Shigo's dissected trees you could clearly see how the living part formed a barrier and the wound was compartmentalized.
I'm a red line cutter too |