As I walk the walnuts - 2

As I walk the walnuts, and given that there are about 2,500 of them it can take quite a while, a discussion ensues: morning wally, g’day wally, looking good wally, etc., etc. My wife will be happy to know that no words are actually spoken, but the occasional murmur after visual inspection is unavoidable. Kahlua occasionally intrudes, with notice that she has uncovered something edible, but generally it is a peaceful intrusion, a thrust of wet nose into the hand. She knows my path, and will meet me at the end of it.

So, to answer your unspoken question, do I prune the trees at all? Well, yes, but probably not in the way you think. Of the 2,500, there are about 1,800 that receive an inspection, generally in March, with a rapid appraisal of growth and form, and perhaps a cut here and a cut there. All inspection is from the top downwards, with most attention paid to serious clefts which could prejudice future strength. I have learned not to worry too much about lack of obvious leaders. The tree has its own means of assigning leadership among its myriad of branches, and it is rare to find instances of consistent competing dominance which could seriously deform a tree. If there is a cleft I don’t like, it is a two-year job to remove it, to avoid a major wound before carbohydrate resources have been reassigned within the tree, increasing relative deposition rate on the full branch remaining. Regular cuts are made above the collar, and the edges of the cut surface trimmed so that as the new cambial layer slowly engulfs the wound it does not have to negotiate right-angled bends in surfaces. A trimmed cut will be covered within half the time, or even less (thank you, Malcolm Olson).

The remaining 700 are still small enough that pruning is a process of early formation, to avoid problems that would make correction more difficult later. But even then a tree is best left alone, with only minor corrections. Splinting or taping to correct obtuse forks is the only exception.

Stay away from bottom-up pruning. It would satisfy the College of Foresters, but it will leave you with fewer future options, reduced growth, and a tendency not to address higher canopy concerns. Let the tree fill all the space it can.