Tree training: Directive pruning helps avoid major pruning headaches
Last month, I received my copy of "Pecan South" which featured a photo of a young tree on the cover (photo at right). One look at the photo and I couldn't help but think this tree had received zero attention since it was planted. The tree had a nice straight trunk that was topped by a cluster of branches growing in every direction. The tree had already lost its central leader.
How can such an obviously strong growing tree lose its central leader so quickly? Yesterday, I was pruning some trees I grafted last year and I think I discovered the answer.
The tree pictured at left was grafted last year. After making some judicious directive pruning cuts last summer, the scion grew a nice straight trunk over four feet in length. However, this spring, the tree burst forth with new shoots from every bud near the top of the tree. If I had let nature take its course, I would end up with with a tree looking very much like the one on the cover of the magazine.
Take a closer look at the top of my young tree (photo at right). Growing from the top of last years wood are at least a dozen new shoots with no one shoot showing any dominance to make a central leader.
An even closer look at the terminal of last year's growth reveals just how many new shoots are growing at the top of the tree. My job now is to identify one of the new shoots to become a central leader and to prune out all others.
I choose to keep a strongly growing shoot that was growing out about 3 inches below the upper-most whorl of new shoots. With a single cut, I could remove a lot of the excessive shoot growth (photo at right).
Next, I followed the 2-foot rule. I pruned off all lateral branches that emerged from the central leader within two feet of the new central leader (photo at left).
After making just these few summer pruning cuts I was left with an actively growing shoot that will become my new central leader (photo at right). Later this summer, secondary buds will break along the main stem to form well-angled lateral branches and to help fill out the tree's canopy.
Over the years, I have learned that leaving a single tender shoot suddenly exposed to our strong Kansas winds is not a good idea. Within days, the exposed green shoot often snaps off in a strong gust of wind. So just like training the shoots growing from a new graft, I used electrical tape to attach a bamboo stake to the woody portion of the tree, then used flagging tape to tie the new leader to the stake (photo at left). Staking the new shoot helps to straighten up the new leader and will prevent both wind and bird damage.