Tree Maintenance and Tree Specifications
Pruning cuts shall be in accordance with ANSI A300 pruning standards (latest edition). Certification is through International Society of Arboriculture, Champaign, IL. An ISA certified arborist shall be on site at least once each day. All work shall be performed by workers trained in accordance with ANSI Z133.1 safety guidelines as required by OSHA.
General Procedures and Techniques
The foliage removed shall be taken primarily from the outer edge of the canopy, not from the interior. No more that 20% of the foliage shall be removed from any tree unless otherwise specified. Dead branches greater than 1.5 inches in diameter (measured at the base of the branch) shall be removed from the canopy of all trees that are pruned. When removing a dead branch, the final cut shall be made outside the collar of the living woundwood tissue. If the collar has grown out along the dead branch stub, only the dead stub shall be removed; the living collar shall remain intact and uninjured regardless of its length. Live branches less than 1.5 inch diameter should not be removed. No live branches or stems greater than 3 inches diameter should be removed from the tree unless otherwise specified.
When removing a live branch at its point of origin on the trunk or from a parent branch, the final pruning cut shall be made in branch tissue just outside the branch bark ridge and collar. No stubs shall be left. (A stub is the remaining branch tissue to the outside of the collar and branch bark ridge.) Live crown ratio should be at least 60% when pruning is completed meaning that no more than the lower 40% of the tree shall be clear of branches.
Removal and reduction cuts shall be used, and not heading cuts.
Never top a tree. Instead prune to its natural shape.
Pruning Treatment Definitions
Head back or remove limbs to increase clearance from buildings, wires, lights, sidewalks, roads, etc.
Legal clearance specifications:
• Walls – 3ft clearance
• Roof – 5ft clearance
• Sidewalk – 8ft vertical clearance
• Chimney – 10ft clearance
• Roads – 12ft vertical clearance
Crown Clean it to include the following: (1) remove dead, broken or diseased limbs 1 inch in diameter or larger; (2) remove rubbing or crossing branches; (3) if two limbs (1 inch diameter or larger) originate within 12 inches of each other on the truck, shorten or remove one of them. (4) Remove weakly attached branches along with suckers and some water sprouts. Do not remove all water sprouts and do not remove only interior branches.
Use directional pruning where possible to future growth is directed away from buildings and lights.
Although small-diameter limbs may occasionally be pruned to gain access into the tree, it will not be necessary to make cuts smaller that 1 inch in diameter, other than where branches may be shortened to accommodate clearance beneath the canopy.
Do not strip out the interior foliage leaving only live branches at the ends of branches.
Underprune to increase ground clearance.
Many trees are over-pruned when the canopy is raised (top right). After proper crown raise, a good goal is to have foliage on branches in the upper 2/3 of the tree (bottom). Live crown ratio should be at least 60%. Small-diameter branches left on the lower trunk for about a year pruning help close pruning would and protect the tree by providing shade to that region. They also help hide pruning wounds.
Cut back appropriate laterals (nothing larger than 1/3 the diameter of where the branch is attached) to reduce the height and/or width of a tree.
Canopy reduction makes a tree smaller by removing the end portion of branches with reduction cute (lower right). Inappropriate reduction uses heading cuts and can result in more problems later (lower left).
Selectively remove limbs to increase light and air in the tree’ canopy, and to reduce wind sail. Thinning shall be conducted by removing branches from the parent branch.
“Lions-tailing” shall not be performed. (Lion-tailing is the practice o removing only the inner branches closet to the trunk on a parent branch and leaving the branches located toward the end of the parent branch.)
Do not remove more than 20% of live foliage unless indicated otherwise.
Appropriate thinning removes small branches from the edge of the canopy (right).
Inappropriate thinning removes only interior and lower branches (left).
All large-growing palms, should be pruned to remove dead fronds, and fronds with a petiole that droops below horizontal.
Dead fronds are those with less than 50% green tissue. All seedpods should also be removed including those originating among remaining fronds.
When removing fronds and seedpods, care shall be taken so those fronds that are to remain are not nicked or wounded.
STRUCTURAL PRUNING FOR MATURE TREES
Develop for a strong dominant leader by shortening competing stems and branches that compete with the stem that will make the best trunk.
Thinning the side of the canopy opposite if the subordination reduction cut improves the appearance of the tree by balancing the canopy. This could help the customer accept this structural pruning technique.
Codominant Leaders and Stems
Codominant leaders are considered to be two or more branches, trunks, or leaders of approximately the same size, originating in close proximity to one another.
Due to the recognized potential hazards associated with the codominant leaders, the subordination (shortening using a reduction cut) or removal of one side of a codominant leader is the primary objective. The main leader should not be subordinated, headed or removed.
YOUNG TREE TRAINING
Train young tree for good form and structure by developing strong dominant leader. Shorten stems that compete with the leader using reduction cuts.
Shorten vigorous, aggressive branches in the permanent nursery canopy using reduction cuts. If two vigorous branches are growing opposite one another, shorten one (lower right branch ‘a’) more than the other (lower left branch ‘b’). The one shortened the most will grow the slowest. The other one will become the one main branch at this point.
HEALTH AND STRUCTURE RATINGS
Note: In order for a tree to be category 5, it must possess all 3 conditions. In order for the tree to fall under categories 4-1, it only needs to satisfy 1 or more of that category’s condition.
– No visible defects in crown, trunk, roots.
– No signs of insects or disease
– Canopy full and balanced
– Minor defects in crown, trunk, roots
– >30% Bark missing from trunk
– No signs of insects or disease
– CanOpy full and unbalanced
– Unequal weight distribution due to trunk lean
– Full canopy lacking
– Trunk displays signs of wood deterioration
– Crown root area displays signs of wood deterioration
– Light insect and disease symptoms
– Some dead limbs
– Trunk area decayed >30% of tree’s x-section
– Decay in >30% of limb’s x-sectional area
– Split trunk
– Canopy die back and unbalanced
– Branch attachment area displays signs or symptoms of wood deterioration
– Extensive portions of root system cut or root rot
– Extensive insect and disease symptoms
– Dead tree
– Crown root area decayed more than 30% of tree’s cross section
– More than 30% crown dieback
– High risk of limb or trunk failure