Wednesday, July 3, 2013

Flooding and new grafts: 2013 results

   Back on June 1, I posted a photo of a newly grafted tree surrounded by flood water (reprinted at right). Unfortunately, the water was still rising when I snapped this photo. Later that night, the graft union on this tree became completely submerged. In my previous post, I stated that a new graft will be lost if flood waters cover the union before the tree has a chance to callus in the scion. Today, I returned to this field to see what actually happened.
    At first glance , the photo at left might look like a successful graft, but all the new growth is coming from shoots that originate below the graft union. Hidden amongst the leaves is a very dead scion. This tree was completely submerged during the flood, giving my grafting effort a 0% chance of success.
      A hundred feet away, I grafted a tree a little higher on the stem (photo at right). This tree was also located on a little higher ground (we're talking 1-2 inches at most). Although this tree was also surrounded by flood water,  the graft union remained above the high water mark.  By escaping the flood, the graft placed on this tree remained viable and is now growing rapidly.
     I grafted about a dozen trees in this field in 2013. In every case, graft unions that became submerged in the flood failed. On the other hand, I've had great grafting success on trees with graft unions placed above the flood's peak. 
    I'll let the trees with failed grafts grow out for a couple of years, encouraging them to grow tall and straight. With a larger tree, I can graft higher on the stem and hopefully avoid future problems with floods.