Sunday, June 15, 2014

Repairing a wind damaged tree

    During the early morning hours, a line of strong thunderstorms rolled through the area. High winds and pounding rainfall woke me up and kept me awake as I listened to the storm whip tree limbs back and forth. Later in the day, I discovered that the wind had broken out the top of a young Greenriver tree (photo at right).
   My first thought was--"Now what do I do? The central leader is gone?".  I walked up to the tree for a closer look at the damage.
    At the point of breakage I discovered two things. First, the vast majority of the wood that broke was healthy (photo at left). A small portion of the stem had been damaged by a flatheaded wood borer. The yellow arrow points to dark tunnels made by the larvae tunneling in the area near the crotch of a side limb. Since the limb broke in the direction away from the wood borer damage, it seems that the insect tunnels created a spot of weakness that allowed a 60 mph gust of wind gust to snap out the top of this tree.
    The second thing I noticed was that the bark had become separated from the wood below the break point (red arrow). By looking over the damage carefully, I formulated a plan to help this damaged tree re-develop a central leader.

    Just above the lowest side limb and just below the area where the bark had separated from the wood, I pruned the tree (photo at right) using my chainsaw. I made a sloping cut that will help foster rapid wound healing. Now all I needed to do was to force the remaining limb to become the tree's new central leader.
    My first step in the tree retaining process was to attach an 8 foot long 2x4 to the trunk of the tree using duct tape (photo at left). I prefer duct tape over nails or screws because it is much easy to remove once the tree wound has healed over. Note that I attached the 2x4 on the side of the tree opposite the one remaining limb.
    Next, I used a orchard ladder to reach the upper portion of the 2x4 and adjacent side limb. Using a nylon rope, I pulled the side limb to an upright position and tied the limb to the 2x4 (photo at right). At this point, the rope is only a temporary fastener. Over time, movement of the tree in the wind can cause a rope to rub right through the bark.  Its time for more duct tape.

    With the rope still holding the limb in place, I used duct tape to secure the limb to the 2x4. To ensure that the duct tape will hold, I applied four layers of tape around tree and 2x4. After taping the limb in place, I removed the rope. At this point, all I have is a side branch raised to an upright position.
    Since I had to remove so much of the tree to repair the storm damage, I decided to postpone  all further pruning until next year. This summer this tree will sprout many new limbs while trying to replace as much of it's lost top as possible. Hopefully, a new central leader will emerge from all the new growth and can begin the tree training process all over again starting next March. I'll keep the 2x4 in place  and the branch tied up until the pruning wound on the main trunk heals over.