Tree Pruning Service SOP

Purpose

Standardize residential tree pruning. The largest recurring revenue line for tree services + the work that builds long-term customer relationships (a healthy pruned tree is a 5-25 year customer).

Scope

Residential ornamental + shade trees up to 60 ft height. Excludes hazard removals (separate Removal SOP), utility-line work (call certified utility arborist), + storm response (separate scope).

Prerequisites

• ISA Certified Arborist on crew (preferred) or in supervision
• Climbing gear: saddle, ropes, lanyards, helmet w/ chinstrap, eye + ear protection
• Spurs (ONLY for removals or when no other access - not for pruning, damages cambium)
• Hand pruners (Felco 2 or equivalent)
• Hand saw (Silky Zubat 330mm)
• Pole saw + pole pruner (12-24 ft reach)
• Chainsaw 14"-18" bar (Stihl MS 201T or equivalent top-handle for in-tree)
• Aerial lift for trees > 35 ft when accessible
• Spray bottle of disinfectant (Lysol or 70% isopropyl) for tools
• Tarps + chipper

Pruning objectives (3 of 5 typical per visit)

1. Deadwood: removes safety hazard + lets tree allocate energy to live tissue
2. Crown raising: removes lower limbs for clearance over walkway, drive, building
3. Crown thinning: selective removal of small live branches to reduce density (15-20% max per visit)
4. Crown reduction: shortening limbs to reduce overall size (carefully - topping is malpractice)
5. Structural pruning: corrects co-dominant stems + competing leaders on young trees

Topping (heading cuts across major leaders) is malpractice + violates ANSI A300 - never quote it; educate the customer who asks for it.

Procedure

Step 1: Walk + plan

1. 360-degree walk around the tree
2. Identify species (pruning timing varies by species)
3. Identify defects: cavities, cracks, included bark, lean, root issues
4. Document existing damage (photo BEFORE work) - protects against claim later
5. Lockout overhead: power lines (10 ft minimum clearance for non-utility crews) + structures

Step 2: Pre-work briefing

1. Crew roles assigned (climber, ground person, drop zone watcher)
2. Drop zone clear of pedestrians + parked vehicles
3. Two-way radio or shouted commands established
4. Tools inspected (chainsaw chain sharp, ropes intact, helmet on)
5. Customer notified work is starting; access permission for adjacent yards verified

Step 3: Ascend safely

1. Tree-friendly climbing: ropes-on-natural-crotch or removable false crotch
2. NO spurs on a tree being kept (cambium damage = 5-year decline)
3. Two-rope system per ANSI Z133
4. Helmet chinstrap engaged

Step 4: Make cuts

Three-cut method for any limb > 1.5" diameter to prevent bark tear:

1. Undercut 6-12" out from final cut location, 1/3 through
2. Top cut 1-2" further out, finishing the cut so limb falls
3. Final cut at the branch collar - NOT flush, NOT a stub

Branch collar: the swollen ring at the base of the limb. Cut just outside it. A flush cut wounds the trunk + invites decay. A stub starves the wound + extends decay.

For small branches (< 1.5"): single clean cut at the branch collar with hand pruners or hand saw.

Step 5: Remove no more than 25% of live foliage in an annual growing season

Read that as per SEASON, not per visit. Two visits at 25 percent each in one season is 50 percent, and the tree does not care that they were separate work orders. Check the file for prior work this season before you cut. Removing more shocks the tree and invites pest and disease. For mature trees, 15-20% is the working maximum.

Step 6: Disinfect tools between trees

Especially in disease-prone species (oaks during oak wilt season - April-July in much of U.S.). Spray + wipe pruners between cuts on diseased + healthy tissue.

Step 7: Ground cleanup

1. Chip + haul or stack to customer preference
2. Rake leaves + needles
3. Sweep walks + driveway
4. Final walk with customer + before/after photos

Acceptance criteria

• Pruning objectives met (deadwood removed, crown raised, etc.)
• No flush cuts or stub cuts
• Less than 25% live foliage removed, counting everything taken off this tree this growing season
• No bark tears
• Drop zone restored
• Customer signed work order + has photos

Timing by species

Best pruning windows:

• Oaks (anywhere oak wilt is present): November-February ONLY (avoid April-July; sap-feeding beetles spread fungus)
• Elms: October-March (avoid Dutch elm disease vector season)
• Maples, birches, walnuts: late summer or late winter (avoid heavy spring sap flow)
• Fruit trees: late winter (dormant) for structure; summer for size control
• Evergreens (pine, spruce, fir): late winter or early spring before new growth
• Flowering trees: just after bloom (so you don't remove next year's buds)
• Dead + damaged wood: anytime - never wait for season

Common pitfalls

• Topping: malpractice. Reduces value of tree + creates hazard
• Flush cuts: trunk wound + decay
• Stub cuts: starves the wound + invites decay
• Too much at once (> 25%): shocks tree
• Wrong season (oaks during oak wilt window): kills the tree
• No two-rope: OSHA + ANSI Z133 violation
• Spurs on a keeper tree: damages cambium permanently
• No disinfectant between trees: spreads disease

Safety considerations

• Two-rope system on every climbing operation
• Aerial lift workers fall-protected + tied to boom
• Drop zone twice the limb length
• No work in storm or high wind (above 30 mph sustained)
• Chainsaw chaps mandatory on ground crew; protective wedge for in-tree
• 10 ft minimum from ANY energized conductor for a crew that is not qualified line-clearance. That includes the service drop. A secondary is still energized, still kills, and does not get a shorter distance just because it is lower voltage. If the work cannot be done at 10 ft, it is a call to the utility or to a qualified line-clearance arborist, not a judgment call on the ground
• First-aid kit on truck + a designated EMT or first-aid trained ground person

References

• ANSI A300 (Part 1) Tree Pruning standard
• ANSI Z133 Safety standard for tree-care operations
• ISA Best Management Practices: Pruning
• OSHA 1910.269 (utility work proximity, non-tree-co-specific)
• Manuall internal: Tree Removal Service SOP, Tree Climbing Safety Reference