Wednesday, March 23, 2011

Graft when the tree is ready

  Increasing grafting success is as simple as being able to recognize when a tree is ready to be grafted. One of the most common mistakes made by pecan growers is to attempt the grafting process too soon after transplanting the rootstock tree. A pecan tree needs a well developed root system to push vigorous growth out of a newly grafted scion. Graft a tree too soon after transplanting and the scion either doesn't take or it grows very poorly.
    The young tree pictured at right has had a hard life. We planted this block of trees during the fall of 2006 using container-grown seedlings. In the spring of 2007, all emerging  new growth was frozen off by the Easter freeze. Three weeks later the trees rebudded. In July of that same year, we had the second highest flood on record. The flood covered the trees, killing the foliage for a second time, and even caused some of the trees to float out of their planting holes. When the flood receded we replanted the floaters and hoped for the best. Miraculously, all but 5 of the 136 trees in this planting survived. In the end, the trees in this block needed an additional year to overcome transplanting and re-establish a strong root system.
   It wasn't until the 2010 growing season that our seedling trees showed the sure sign that 2011 would be the year for grafting. New shoots grew over 2 feet in a single season. The tree pictured above actually had 2 flushes of new shoot growth in 2010, indicating that the roots were really ready to push new top growth. (Zoom in on the photo and you'll see that the second flush came from stalked buds)
    You'll note that the form of this tree is far from perfect--branches growing every which way. Not to worry. In late April, I will be grafting this tree. I'll cut the tree off below all the branches and place a bark graft at that point. Once the bark graft starts growing, I'll prune the scion down to one bud and train that new shoot to the straightest most vigorous central leader tree imaginable. Grafting when a tree is ready not only increases grafting success but also makes training a young tree a whole lot easier.