Buying High-Quality Trees
|
|
When you buy a high-quality tree, plant it correctly, and treat it properly, you and your tree will benefit greatly in many ways for many years.
When you buy a low-quality tree, you and your tree will have many costly problems even if you take great care in planting and maintenance.
|
What Determines Tree Quality?
A High-Quality Tree Has:
1. An adequate-sized root ball. If possible, check to ensure there are enough sound roots to support healthy growth.
2. A trunk free of mechanical wounds and wounds from incorrect pruning.
3. A strong form with well-spaced, firmly-attached branches.
A Low-Quality Has:
1. Crushed or circling roots in a small root ball or small container.
2. A truck with wounds from mechanical impacts or incorrect pruning.
3. A weak form where stems squeeze against each other or where branches squeeze against the trunk.
Any of these problems alone or in combination with the others will greatly reduce the tree's chances for a long, attractive, healthy, and productive life.
When buying a tree, inspect it carefully to make certain it does not have problems with roots, injuries, or form. (Remember "R.I.F" - it will help you remember Roots, Injuries, and Forms.)
|
Injuries
Beware of injuries beneath trunk wraps. Trunk wraps may hide wounds, incorrect pruning cuts, and insect injuries. Never buy a tree without thoroughly checking the trunk. If the tree is wrapped, remove the wrap, inspect the trunk for wounds, incorrect pruning cuts and insect injuries. Wrap can be used to protect the trunk during transit, but should be removed after planting.
Incorrect pruning cuts are major problems. Incorrect pruning cuts that remove or injure the swollen collar at the base of branches can start many serious tree problems - cankers, decay, cracks.
Incorrect pruning cuts that leave branch and leader stubs also start disease and defect problems. Do not leave stubs.
A correct pruning cut removes the branch just outside of the collar. A ring or "doughnut" of sound tissues then grows around the cut. Do not make cuts flush to the trunk. The closing tissues may form only to the sides of the flush cuts. Trunk tissues may form only to the sides of the flush cuts. Trunk tissues above and below flush cut branches often die. When the heat of the sun or the cold of frost occur, cracks or long dead streaks may develop above and below the dead spots.
|
|
Forms
Good, strong form, or architecture, starts with branches evenly spaced along the trunk. The branches will have firm, strong attachments with the trunk.
Squeezed branches signal problems. Weak branch unions occur where the branch and trunk squeeze together. As the squeezing increases during diameter growth, dead spots or cracks often begin to form where the branch is attached to the trunk. Once this problem starts, the weak branch attachment could lead to branches cracking or breaking during mild to moderate storms.
When several branches are on the same position on the trunk, the likelihood of weak attachments and cracks increases greatly. As the branches grow larger and tighter together, the chances for splitting increase.
Avoid trees with two or more stems squeezing together. As stems squeeze together, cracks often form down the trunk. The cracks could start from squeezed multiple leader stems, or where the two trunks come together.
If you desire a tree with multiple trunks, such as a birch clump, make certain that the trunks are well-seperated at the ground line.
Remember, trunks do expand in diameter as they grow. Two trunks may be slightly separated when small, but as they grow in girth, the trunks will squeeze together.
Look for early signs of vertical trunk cracks. Examine branch unions carefully for small cracks below the unions. Cracks are major starting points for fractures of branches and trunks. The small cracks could be present for many years before a fracture happens. Always keep a close watch for vertical cracks below squeezed branches and squeezed trunks.
Corrective pruning helps. If your tree has only a few minor problems, corrective pruning may help. Start corrective pruning one year after planting. Space the pruning over several years. Remove broken or torn branches at the time of planting. After a year, start corrective pruning by removing the branches that died after planting.
|
Trees Have Dignity Too
Most nurseries produce high-quality trees. When you start with a high-quality tree, you are giving that tree a chance to express its dignity for many years. Remember RIF.
|
Developed by the International Society of Arboriculture, a non-profit organization supporting tree care research around the world and dedicated to the care and preservation of shade and ornamental trees. For further information contact: ISA, P.O. Box 3129, Champaign, IL 61826-3129, USA
|
|
