Tuesday, June 4, 2013

Sprouts from a drought-injured pecan tree

   Last summer's heat and drought was hard on a lot of plants including young pecan trees. This morning, I photographed a tree that I had grafted two years ago (photo at right). I was so disappointed; I lost almost the entire top of the tree to drought-induced die-back. This tree had been growing great, with over 4 feet of new top growth added just last year.  But if you look at the tree now, all you will see is a few new sprouts growing from the base of the tree.
     The photo below is a close-up of the sprouts that are now growing from the tree's base. Notice that the sprouts seem to come in one of two different colors. The sprouts with a reddish tinged leaves are growing from the rootstock portion of the tree (below the graft). Red pigmentation of expanding new leaves is a juvenile characteristic of a seedling pecan tree.

    The bright green sprouts have developed above the graft union. The all-green color is indicative of sexually mature tissue and tells me that these sprouts originated from the Kanza scion. 
    Now, the tree training process must start all over again, but this time with a twist.  First, I removed all the sprouts with red colored leaves. Next, I pruned off all but one of the green "Kanza" sprouts in an effort to restart a central leader. For the time being, I left the dead portion of the old trunk in place to act as a training stake for the new shoot. To keep this tender shoot from being broken off by a wind storm, I used grafting tape to tie the shoot to the old trunk.
    I'll cut the dead portion of the old trunk out in mid-summer once the new shoot has developed a woody stem of its own.  However, this tree will still need staking. Until the pruning wound is completely healed over, this tree will be prone to wind breakage at the point of connection between new central leader and older trunk.  Once I remove the dead stem, I'll use an eight foot long piece of steel conduit (3/4 inch tubing) as a stake for tying  at the new leader.
    After pruning I installed a deer cage around this tree. In the photo above, you can see that a deer had already sampled the succulent new growth sprouting from this tree.  With all the root energy pushing my new central central, I should see at least 5 feet of new growth this summer. If the deer, were allowed free access to this tree, I'd end up with a 2 foot tall pecan bush.