Who is a tree worker? The Occupational Safety and Health Administration (OSHA) spent a lot of time and effort defining this – through the questions they asked of small business representatives during SBREFA (Small Business Regulatory Enforcement Fairness Act) – concerning the scope and application of a proposed rule. It seems that OSHA’s preliminary determination is that a rule should apply to all workers engaged in tree care operations, regardless of whether they are employed by a grounds-maintenance, landscape or tree care company.

The application of a standard by activity – such as ornamental tree care – rather than by company name makes sense. There are about 30,000 tree care companies and another 74,000 landscape companies in the United States. But many of these companies’ offerings have blurred lines, and they perform both tree care and landscape services. An internet search of companies with “tree and landscape” in the name will yield multiple pages of results. There also are many more single-proprietor establishments – the most operations in either industry – that may perform a wide range of services from lawn care and general landscaping to tree care.

There has been some thought that landscapers perform their tree operations – removals and pruning – only on smaller trees, i.e., those less than 12 or 15 feet tall. Some say this is not “real” tree care and should be exempt from any tree care-operation standard. True, incidents to landscape-services workers often occur in 15- to 30-foot-tall trees, but the workers still were injured or killed. They also have died while working at 30 to 60 feet in tree canopies.

But what differences occur in tree-related fatal incidents involving workers employed by tree care companies and those employed by other landscape services? In this article, we will look at the difference in fatal incidents in recent years between these two groups – tree workers employed by tree care companies and landscape-services workers employed by grounds-maintenance and landscaping companies.

The data comes from OSHA fatality reports and the U.S. Bureau of Labor Statistics (BLS) industry summaries for landscaping, lawn maintenance and tree care. The BLS Census of Fatal Occupational Incidents, which includes fatal incidents among a larger group than OSHA investigates, was used as well. We also looked at hospital admissions and fire & rescue/emergency-medical-services reports, among other sources. The data was cross-referenced to avoid counting incidents twice. The data covers 2022 through 2024.

Overview of workforces
There are slightly more than a million landscape-services workers (“landscape workers” for brevity) in the U.S. There are an additional 300,000 tree workers. The median age of a landscape worker is 42 years old, while the median age of a tree worker is younger, about 37. About 12% of the tree care workforce is 55 or older, while for landscape workers, this percentage increases to 22%.

Landscape workers tend to be older but die on the job younger. The average age of fatal incidents for all landscape workers is 37. If we look at incidents involving tree care workers, the age increases to 41. The median age of the fatalities does not correlate to the median age of the two workforces.

The reason for this difference may be related to the most common hazard sources. Transportation incidents are the most frequent fatal events for landscape workers but represent only a small percentage of tree-worker incidents. About 30% of all landscape-
worker fatalities are transportation incidents, mostly non-roadway events involving vehicles. These fatalities disproportionately occurred to workers under 25 years old.

Ground-maintenance workers using string trimmers near roadsides have been fatally struck by vehicles that drove over the curb. Vehicles leaving the road and entering the median strip also have resulted in many fatalities among mowing crews. These tend to be job duties of younger workers in the industry.

Tree-related fatalities
Tree care operations are hazardous regardless of whether being undertaken by a tree worker or a landscape worker. Almost all tree-worker fatalities occur during tree care operations. There are exceptions. A tree worker was electrocuted while stringing Christmas lights on a house, for example. Another tree worker died while mowing a solar farm.

By contrast, about 40% of landscape-worker fatal injuries occur during tree care operations.

While we can cover the different incidents between tree workers and landscape workers, a calculation of incident rates is not possible. There is no way of determining whether a landscaper just happened to be engaged in tree care on the day of an incident, and the rest of the year was installing landscapes, or if they were pruning and removing trees every week. The lack of this information prevents calculating any meaningful full-time-equivalent (FTE) comparison.

Power equipment – chain saws, chippers and stump grinders
What are some other differences in fatal incidents between the two groups? First, there are more incidents involving chippers and stump grinders among tree workers than landscape workers. This may relate to the size of the trees on which the work is being performed. There is not a lot of need for this equipment for smaller trees.

While most fatal incidents with chippers and stump grinders occurred to tree workers rather than landscape workers, there was no difference in how the incidents unfolded. Chipper fatal incidents were more pull-throughs from kicking in brush while standing on the infeed table, a fatal injury described as total body maceration. Others were struck by a rope that became tangled in the brush fed into the chipper. There are always a few fatalities from workers opening the access hood while the chipper is running and being struck by the hood, a broken knife or debris. Landscape workers sometimes operate rental equipment, and may have been working with little to no instruction.

Stump grinders were involved in more fatal incidents than chain saws, a recent trend we have seen. The stump-grinder incidents were, as with chipper incidents, either the workers being pulled into the grinding wheel or struck by a rope pulled into the grinding wheel. One incident involved a worker attempting to pull out roots while the machine was operating; they lost their balance when a root snapped, and the worker’s head struck the spinning wheel.

Landscape workers share these same incidents, but many of their stump grinders are rentals and smaller-sized machines. The rental units may not come with an instruction manual, and any training on their operation may be minimal or absent. One of the more horrific incidents was when a landscaper wrapped a rope around his body to help pull the stump grinder over a stump. The rope caught in the wheel and pulled the worker headfirst into the cutting wheel.

Chain saws are involved in many incidents that require trips to a hospital emergency department, but not many deaths. Almost all the fatal incidents involved workers aloft, whether tree or landscape workers. The canopy environment is where we can be operating chain saws in awkward positions, without any cut-resistant clothing and far from help if a deep laceration occurs.

A common denominator in these incident reports was that no one could reach the worker in time to control the bleeding. One incident involved a lawn-care worker who climbed 40 feet into a tree and was pruning with a chain saw. The spinning chain struck his arm, resulting in deep lacerations. He was unable to descend on his own. Fire & rescue reached the injured worker and brought him to the ground in a Stokes basket about 50 minutes later. The worker was transported to the hospital, but later died from the injury.

Falls to lower level
Falls were still a common fatal event for both tree and landscape workers. Tree-worker falls from trees were mostly due to anchor failures – the branch supporting their climbing line or lanyard failed – or cutting their single fall protection, i.e., their climbing line or lanyard. By contrast, landscape workers frequently fell while they free-climbed (climbing without fall protection) after entering the tree by a ladder. There was only one incident of free-climbing among the tree-worker-fall fatalities.

The hazard source for falls from aerial devices differed between the two groups. Tree-worker falls involved operators not secured by a fall-arrest or fall-restraint system. They often fell when the boom was jolted by a falling branch and the unsecured operator fell out. Another common event was the operator overreaching while cutting a branch with a chain saw and falling out as the branch fell.

Landscape-worker falls from lifts had additional contributing factors. This group used a wider range of aerial devices – some that do not fit the definition of an aerial lift. Landscape workers suffered fatal falls when the home-made basket resting on the pallet-fork attachment of a skid steer slid off. They also fell from buckets – not work-platform buckets – attached to telehandlers while pruning trees.

They sometimes rented aerial devices and, as seen with rental chippers and stump grinders, received very little to no instruction in their operation nor obtained an instruction manual. The falls from rental aerial devices were often from the operator not wearing fall protection. But fall-protection equipment is not included in the rental of these units, nor can it be rented. While this may seem foolish on the part of rental companies, the frequently cited reason is that the rental company cannot be certain it was not damaged or used improperly. Many will sell fall-protection equipment, but not rent it. Since it does not come with the unit, landscaper-services workers will operate these devices without any fall protection.

Falls from ladders or roofs while pruning most often occurred to landscape workers. They were pruning with a chain saw or pole saw while standing on the ladder. Either the cut branch swung into the ladder, knocking the worker off, or they lost their balance once the pole saw finished the cut.

Contact with objects and equipment
Struck by a falling tree was the most common event in this category. There were more landscape workers than tree workers killed by falling trees. There was also a difference in who died between tree workers and landscape workers. The chain-saw operators and ground workers were killed at the same rate by a falling tree among tree workers, while for landscape workers it was disproportionally a ground worker struck by the falling tree.

The most common reason a chain-saw operator was killed by a falling tree, regardless of group, was failure to move along a retreat path. Most were standing near the trunk when the tree either fell in an unintended direction or kicked back off the stump. A few were killed when the falling tree struck a second tree and that tree, or a limb, fell back on the chain-saw operator.

Many of the ground workers who were struck by a falling tree were involved workers – those tending a pull line. The fatal error was often misjudging the strike distance of the falling tree (or their ability to outrun it). But there were some fatalities, mostly landscape workers, where the tree was the secondary hazard source. They were not struck by the falling tree but by a snapped rope. These workers were in skid-steers or loaders and were attempting to pull over the tree being cut. The pull ropes snapped due to the strain, and the recoiled rope fatally struck the worker in the cab.

Struck by a falling limb was another frequent incident for both groups of workers, though slightly more often this occurred to landscape workers. The most common scenario for landscape workers was a ground worker walking into an active drop zone and being struck by a falling branch that was cut without warning. While this type of incident also occurred to tree workers, tree workers also had climbers and aerial-device operators struck by branches they had just cut.

Palm asphyxiation also is included in this event category. A worker climbs beneath the skirt of dead palm fronds and begins to cut them. The cut fronds often do not fall immediately, but become lodged in adjacent fronds. Once a critical number is cut, a portion of the skirt breaks loose, enveloping the climber. The pressure of the mat on the neck and chest can restrict breathing, resulting in death by asphyxiation. These incidents mostly occur to landscape workers and the self-employed. The number of deaths due to this hazard source is difficult to determine due to the transient nature of the workforce. Many are day laborers.

We also have seen a few asphyxiation deaths not involving palms but (real) trees. A climber for a tree company became entangled in a rigging line and the cut branch and was asphyxiated. An aerial-lift operator had a malfunction with the bucket control and was pressed into the side of the trunk and asphyxiated.

Exposure to harmful substances or environments
Exposure to electricity is the most common fatal event in this category for tree workers and landscape workers. Most of the electrical contacts were to tree-company climbers, and involved indirect contact via the branch they had just cut and were holding, or through a conductive tool such as a chain saw. These same incidents occurred with tree-company aerial-lift operators.

Landscape workers were more likely to be electrocuted while standing on a metal ladder and holding a metal pole pruner that contacted an overhead power line. They also were electrocuted while standing on metal ladders and shearing tall hedges with gas-powered or electric, corded hedge trimmers. One landscape worker climbed about 50 feet into a tree to prune branches. He was attempting to untangle a cut branch from an overhead power line when the pole pruner contacted the line.

While most of the electrical-contact incidents were via indirect contact, there were some where workers touched the overhead power line. All were climbers, but not all were tree workers. Some landscape workers also were electrocuted while climbing a tree.

Exposure to temperature extremes is included in this event category. This was the hazard source for a few incidents to both tree workers and landscape workers. All were heat injuries. Crew members failed to recognize the signs of heat exhaustion in a co-worker. The affected workers slipped into heat stroke and died.

Also classified within this event category are accidental drug overdoses. This event is becoming an increasingly common workplace fatal incident in general – almost 10% of all occupational-worker deaths. Unfortunately, tree workers and landscape-services workers are not exempt from these incidents. Opioids and alcohol were secondary factors in several fatal incidents, including one when a tree worker fell into a swimming pool and drowned.

Conclusion
Tree care operations are not exclusively within the realm of tree care companies. Landscapers and ground-maintenance workers also are employed to work on trees. They comprise about one-quarter of all the ornamental tree care-operation fatalities. These workers also should share in the same training and adherence to safety standards and regulations as tree care workers.

John Ball, Ph.D., BCMA, CTSP, A-NREMT (Advanced-National Registry of Emergency Medical Technicians), is a professor of forestry at South Dakota State University.

Mike Tilford, CTSP, is director of general tree care based in Ft. Collins, Colorado, for SavATree, a 40-year TCIA member company headquartered in Bedford Hills, New York. He is an ISA Certified Arborist, an ISA Certified Municipal Specialist, an ISA Certified Tree Worker – Climber Specialist and an ITCC head judge and gear inspector. He is also a new member of TCIA’s Board of Directors.

This article is based on Ball’s and Tilford’s presentation on the same subject during TCI EXPO ’24 in Baltimore, Maryland.