Vance Wood
Lord Mugo
I had not heard that it has anything to do with age or health. I don't think anyone knows what causes it. I have had it on vigorous years, and on slow years. Maybe winter cold has something to do with formation.
You have such potential with this tree, would be a good puzzle to solve!
It is possible this runs in cycles. I found out after three or four years researching and asking questions of people who are supposed to know; Pinion Pines run in five year cycles in producing bumper crops of cones. Understanding that cone production was important to the native populations a century and a half ago this kind of information becomes vital. I am suggesting that this too may be the result of a cycle. I don't know how many years but it seems that there may not be a trigger as some expect. JMHO