Anatomy and Function of a Deciduous Tree
Trees that shed leaves every year are considered deciduous. It is important to understand the anatomy or support framework of deciduous trees, before you start pruning.
The tree’s upper-ground section consists of the trunk and scaffold branches. The trunk’s leader is the vertical stem that rises from the top. Scaffold limbs are the primary limbs that create a tree’s canopy. Secondary branches that arise from scaffold branches can be called laterals. Growth is from buds located at the tips or along branches’ sides (terminal buds).
Two types of vigorous shoot growth are commonly considered undesirable: water sprouts and suckers. Water sprouts can be found on branches. Suckers are plants that grow from the roots or trunk.
Imagine how branches are attached to the trunk during pruning. The branch collar refers to the swollen trunk tissue area around the branch’s base. The branch bark line is a line that runs from the trunk bark to the branch-trunk cross. It can be less prominent on some trees but it can be seen on others.
What to Prune
Corrective pruning eliminates rubbing branches and removes any damaged wood. If you are pruning diseased or dead branches, cut into the healthy wood at least one meter below the affected area. Between each cut, disinfect the tools with products like Lysol, Listerine, or rubbing aloe. The tests have shown that household bleach, “Pine-Sol”, and household bleach can be very corrosive to tools.
Avoid rubbing or poorly-placed branches and remove them as soon as you can. Water sprouts, suckers and other problems with normal growth can be prevented by pruning them as soon as possible.
Young tree pruning is used to train and prevent future problems. Pick permanent scaffold branches with wide angles that attach to the tree. An area of weakness in the future will be indicated by a branch’s attachment angle that is too narrow. Branch attachments should be evenly spaced, at least 10-12 inches apart, and placed radially around the trunk. You should not let one limb stand directly above the other, shading it out. If you are looking for multi-stemmed trees, train the tree to only have one leader.
Replace the tree’s leader if it is damaged or killed by storms. Prune all laterals immediately beneath the new leader. Use flexible wire or wood splints and then remove them after a single growing season.
Prune to change the natural growth pattern of trees. To make your tree more open, you can leave the terminal buds on all scaffold branches. But, cut or eliminate any laterals. To make a taller tree, cut all branches to 8 feet high as soon as there are three to four scaffold limbs. To make the tree compacter, cut all scaffold branches in half, remove outward-facing flowers, and let most laterals develop.
How to prune
There are two types of pruning cuts you should know about: heading cuts and thinning cuts. Heading cuts are used to reduce the height of trees by removing terminal flowers and cutting back lateral branch. Heading cuts stimulate the growth of buds near the cut. The direction of new growth is determined by the direction the top lateral bud remains. Avoid using topping (also known heading) on branches more than one year old to discourage unwanted water sprouts. Also, topping and heading can disfigure older trees, compromise the tree’s structural integrity and expose large areas to insects and diseases.
Thinning removes branches from their origins or attachment points. You are thinning when you trim a branch to the trunk or a branch to another branch. Thinning cuts encourage tree growth, not just in one branch as with heading cuts. Drop crotch is a type or thinning that reduces the size of trees while maintaining their natural shape. For a drop in crotch, choose and remove higher branches. Thinning can improve air circulation, sunlight penetration, wind resistance, and provide better air circulation.
Properly prune your branches. Cut 1/4 inch above a lateral branch to make heading cuts. Make sure you slope down away from the buds. The bud could die if you cut too close or at an unfavorable angle. To thin larger branches, you should cut at a 45-60 degree angle from the branch bark. The branch collar should be left intact in order to quickly heal the wound and prevent any decay from entering the trunk.
