Wednesday, July 27, 2016

Storm damages young pecan tree

   A strong wind during a mid-summer thunderstorm can undo years of careful tree training.This was the case when I discovered a tree broken over and laying on the ground (photo at right).

     It seems the force of the wing was so strong that it bent the tree over so far that the main stem fractured into hundreds of splinters (photo at left).  Fortunately, I paint the graft union white on all my trees to provide an easy visual record of which trees are grafted and which are not. This tree broke well above the graft union so I could use one of the small branches below the break to serve as a new central leader. 

    After looking over the tree, I decided to cut the damaged trunk off just above a small lateral limb. At first, I thought it would be a good idea the start cutting at a point just above the side shoot (photo at right). However, cutting into the curve of the break meant that all the downward force of the broken tree was working to bind the saw in its kerf. I quickly pulled the saw out and opted for a different angle of attack.

     By cutting the tree on the back of the break, I soon learned sawing through the wood was much easier (photo at left). The weight of the fallen tree was pulling open the saw kerf allowing the saw blade to move freely. However, cutting from this direction meant that I had to draw an imaginary line across the stem so I would finish the cut just above the point that little side branch. I also needed to trim this trunk at a 30 degree angle just like we do when trimming up a bark graft.

      After making the angled cut across the trunk, the tree looks just like a recent bark graft (photo at right). However, unlike a bark graft, I decided to leave emerging stump sprouts above the graft union to grow for the rest of this summer. This tree has suffered a tremendous loss of leaf area in the middle of the summer and these emerging shoots will help shade the trunk to prevent sun scald to the trunk. Next year, I'll go back to proper pruning and training to make sure I develop a well structured tree.

    To help train the remaining small side shoot into a new central leader I drove a 1 x 2 inch wooden stake in the ground next to the trunk. I then secured that stake to the trunk of the tree with black electrical tape. Next, I carefully lifted the side shoot to an upright position. If I pulled too hard, I ran the risk of breaking the shoot off the tree. After pulling the shoot upright, I used green flagging tape to hold the branch in position (photo at left).
   It will take a couple of years to heal over the wound created by the break in the trunk. I'll keep the new central leader tied to the stake until the healing process is complete.