i. Pruning is defined by the Tree Care Industry Association (TCIA) to be “Class II – medium pruning”. Topping shall not be permitted; however, directional pruning and drop-crotching are permissible. Safety requirements of ANSI, Section 5, 8, and 9 (exclusive of paragraphs of sections expressly deleted) shall regulate the work. 1. Spurs or Climbing Irons: Spurs or climbing irons may not be used on any City trees except those approved for removal by the Chief Urban Forester or designated representative. 2. Sterilized Cutting Tools: Where directed by the Chief Urban Forester or designated representative, denatured alcohol or antifreeze shall be used to sterilize tree cutting tools and equipment. 3. Acceptable Cutting Techniques: Branch collars shall always be left intact. Stubbing of branches is not permissible; either the branch must be pruned entirely or cut off to a substantial lateral. Tearing, ripping, or pulling of branches is prohibited. Only handsaws, power saws or tools, pole saws or pruners are to be used to make cuts. No portable electric tools are to be used in any trimming work, thus omitting paragraph 6.1 of ANSI-Z133, 1-1979. Paragraphs 6.2 and 6.3, however, shall apply. 4. Pruning Heights: Parkways’ standard pruning height for truck and parage routes is eighteen (18’) feet. Parkways’ standard pruning height for residential streets is sixteen (16’) feet. Parkways’ standard pruning height is to provide ten (10’) of clearance over public and private structures unless noted otherwise on the work order. Contractor shall make every effort to provide these pruning heights. If these pruning heights cannot be provided, Contractor will notify the Chief Urban Forester. 5. Disease and Infestation, etc.: All dead, fungus or insect infested branches down to one inch (1”) diameter should be cut off to a healthy crotch, so that healthy tissue surrounds the final cut. If it is not possible to cut it off without stubbing a branch, the entire branch must be removed, or cut back to a substantial lateral branch that will project future growth in the proper direction without weakening the branch. All limbs exceeding one inch (1”) in diameter must be precut to prevent splitting. It is strongly recommended using ropes so as to avoid turf and/or pavement damage for which the contractor will be held responsible. 6. Branches in Contact with Structures, etc.: Any branches that are in contact with a structure should be removed back to the main trunk or principal lateral, so that at least a ten foot (10’) clearance between the tree and the structure is provided, when possible. If contractor has concerns regarding this specification, they should contact the Chief Urban Forester for resolution. 7. Branches Damaged by Vehicles: Branches that have been damaged by vehicles are to be removed to a substantial lateral branch that will project future growth in the proper direction without weakening the branch. 8. Branches Interfering with Streetlights and Traffic Signals: Branches of this type shall be trimmed to provide for three feet (3’) of clearance around the light. Traffic signals are to be visible by motorist for at least one hundred fifty feet (150’) away from any given traffic signal. 9. Suckers, Water Sprouts, and Vines: Suckers, water sprouts, or vines on tree trunk and/or major branches, including those grown from the root system, shall be removed flush with the main stems or with the ground. 10. Structural Pruning: Structural Pruning is defined by the International Society of Arboriculture to be “the removal of live branches and stem to influence the orientation, spacing, growth rate, strength of attachment, and ultimate size of branches and stems.” Structural Pruning shall be completed in accordance with the arboriculture practices as per companion publication to ANSI A300 Part I, “Best Management Practices: Tree Pruning (Revised 2008)”, published by the ISA, P.O. Box 3129 Champaign, IL 61826-3129. Structural Pruning may be requested by the Chief Urban Forester and should be included in the bid price.
