Wednesday, December 19, 2012

Protecting young pecan trees against deer damage

     Deer populations across the US have exploded making it increasingly difficult to grow young pecan trees. The photo at left illustrates the most common form of deer damage--buck rub.  Buck deer rub their antlers on 1 to 2 inch diameter pecan trees to remove the velvet from their antlers and mark their territory in preparation for mating season. They choose small diameter trees that are strong enough not the break under rubbing pressure but limber enough to snap back against the antlers as the animal moves his head from side to side. The result of all this rubbing is the complete removal of the bark from a large portion of the lower tree trunk. Come next spring, I will cut this tree off just below the buck rub and place a bark graft on the stump.

      After I graft a tree, I install a deer cage around the tree to protect the new graft from deer browsing (photo at right). The cage is constructed from six feet of 5-foot-tall welded wire fencing (2 inch by 4 inch grid). I use a steel fence post to hold the cage in place (tied with baler twine). In the photo, a bamboo stake is attached to the tree to provide support for the growing graft.                       I leave the deer cage around the tree until it has grown large enough to heal over the bark graft union and tall enough to emerge out of the top of the cage. During the growing season, I remove the cage at regular intervals so I can prune the tree according to the 2-foot rule. After every pruning session, I re-install the cage.  
      Once a grafted tree has grown large enough to provide me with 3 feet of  clear trunk, I remove the welded wire cage and replace it with a plastic trunk protector (photo at left). These trunk cages look like there are made out of 1 inch by 1 inch welded wire but they are actually a very stiff plastic material formed in a 6 inch diameter cylinder. The trunk guard is split along one side so you can slip the guard around the tree. I use baler twine to close the edges of the tree guard together so it forms a complete cylinder around the trunk. The primary purpose for installing these trunk guards is to prevent buck rub and so far they have done a great job. I'll leave the trunk guards in place until the tree has grown to about 5 inches in diameter. At that point, the deer seem to leave my trees alone (Although, they do like to eat any nut that hits the ground).