CABLING: This is not a do-it-yourself project. An arborist needs to determine the right height for one or two cables, he’ll climb the tree and drill a hole through each main branch and insert a threaded, galvanized eyebolt that is held in place with a large washer and two nuts. The two eyes are connected using steel cable. To keep the trunk from splitting, he may also drill crisscrossing holes through the trunk for threaded rods.The tree will eventually grow over and hide the rods, but it can’t be allowed to cover the eyebolts, which have to be inspected, and perhaps adjusted, every year or two as the trunks grow.