Tree Health

The Key With Fall Fertilization

Apply late in season for fall root growth and storage in plant tissues for use in spring
By John Fech


Fertilization programs are utilized to maintain the vigorous and healthy growth of trees and to increase their resistance to damage from insects and diseases. When applied judiciously they can be a valuable part of a plant health care program.

The foundational tenet of tree fertilization is that it should be an as necessary procedure, not a standard, one-size-fits-all program.

Fall versus spring

When needed, there are two general time frames to fertilize trees: early to mid-spring and late fall when plants are dormant. In spring, applied nutrients are converted to essential plant compounds – sugars, carbohydrates and amino acids – that bolster stem, trunk and root growth. In late fall, some nutrients are used in root growth, with the remainder stored in other plant tissues ready to be used when the roots resume absorption and expansion in the spring.

Early fall applications aren’t recommended because the resulting encouragement of growth that often occurs may not have adequate time to harden off before the onset of winter. If not winter-ready, the stems have a greater potential to suffer winter injury because of their soft and supple nature. Depending on where you live, root function can continue into December.

The amount of fertilizer applied in fall versus spring should also be considered. A good rule of thumb for fall applications is to apply about a third of the amount normally used for spring applications – enough to encourage root and future shoot growth, but not more than will be absorbed. Judicious applications don’t facilitate ground or surface water pollution. Slow-release nutrient formulations decrease the odds of leaching and runoff, but always use caution when fertilizing trees.

Undersized or pale leaves are good indicators of the need for fertilization.

Determining need

When determining whether to fertilize and how much, lean on factors such as soil testing, appearance, growth rate and the surrounding plant material in the landscape.

Soil testing – The critical indicators provided by a soil test report are nitrogen, phosphorous, potassium, pH, secondary nutrients and the micronutrients. Cation exchange capacity, salt index, sodium absorption ratio and organic matter content should also be considered when determining need.

Before submitting a sample for soil testing, ask the testing lab how to best obtain a representative sample for the appropriate testing procedure and follow their instructions carefully. Once the report is back, consider the tree and its specific needs. For example, if the tree in question is a red maple or pin oak in northern Illinois, the soil test report is likely to indicate a high pH and a suggestion to lower it to make the iron in the soil more available. As such, it’s important to match up the specific needs of the tree species with the test results.

When to Fertilize

  • Do apply in the late fall.
  • Do consider the amount of fertilizer applied in fall versus spring. A good rule of thumb for fall applications is to apply about a third of the amount normally used for spring applications – enough to encourage root and future shoot growth.
  • Do consider nitrogen, which is generally the nutrient required in the greatest quantity for fall fertilization.
  • Do fertilize if a tree’s foliage is pale green, a tree has undersized leaves, a thin canopy is present, or stems have dieback.
  • Do fertilize if a tree is growing in a mulch bed or in a parking lot. These landscape spaces don’t offer the benefit of nutrients applied to turf.
  • Do fertilize if a tree that grows at a rate typical for its species for several years is followed by a decline in growth rate over successive years.

When Not to Fertilize

  • Don’t apply in the early fall when fertilizer can encourage growth. Depending on where you live, root function can continue into December.
  • Don’t apply if trees have root damage from construction or trenching.
  • Don’t fertilize if a tree is in the middle of a lawn that receives nutrient applications, as small amounts of the applied materials will move downward in the soil profile and be absorbed by the tree roots.
  • Don’t fertilize trees under stress.

Species aside, nitrogen is generally the nutrient required in the greatest quantity. However, because it is a mobile nutrient, test reports tend to be transitory and reliable only for a short time. As a result, it’s common for soil tests to indicate a need for low to moderate amounts of nitrogen and that an adequate amount of phosphorous and potassium, which are more stable and required in lesser quantities, already exist. Again, good communication with the soil-testing lab is essential.

Appearance – The color of foliage, condition of the branch tips, size of leaves, thickness of crown, and comparison with other specimens of the same species are good indicators of the need for added nutrients. If foliage is pale green, the tree has undersized leaves, a thin canopy is present, or stems have dieback, fertilization may be beneficial.

Trees with root damage from construction or trenching should not be fertilized.

Surrounding plant material – If the tree is in the middle of a lawn that receives periodic nutrient applications, the need for tree fertilization is reduced, as small amounts of the applied materials will move downward in the soil profile and be absorbed by the tree roots. If grass clippings are returned to the lawn during mowing operation, then small amounts of the nutrients present in the grass blades are recycled to the soil, where both grass and tree roots can grab them.

The situation is different for a tree growing in a mulch bed or in a parking lot. Neither of these landscape spaces offer the benefit of applied nutrients to turf; however, depending on the amount of leaf debris that’s recycled back to the tree roots, the need will change. In mulch beds, the decomposition of debris that falls on the mulch layer is helpful in maintaining the fertility level of the soil, thereby decreasing the need for added nutrients. Parking lots, on the other hand, offer little potential for turf fertilizer or tree debris to encourage healthy tree growth. Fertilization may be helpful in landscapes that offer minimal inputs. In addition, fertilizer injections may be best in these scenarios, as they are generally not conducive to water lance or surface applications.

A thin crown can indicate a need for fertilizer if other factors are not limiting.

Regardless of the application method, the rate should be based on the area occupied by the roots. Unless severely restricted because of planter boxes or tree pits, roots typically spread well beyond the branches on established trees and shrubs. Therefore, the target area for fertilization should be two to three times beyond the diameter of the branch spread.

Growth rate over time – A tree that grows at a rate typical for its species for several years followed by a decline in growth rate over successive years should be considered a candidate for fertilization. If a slowed growth rate is observed in conjunction with an indicated need in a soil test report for a tree in an area that is well aerated but not routinely fertilized (such as an ornamental bed), then a low to moderate application of nitrogen and other elements may be useful in improving the tree’s health.

On the other hand, if a tree has been receiving nutrients from lawn applications, has received adequate rainfall, and there are no visible pests, then added nutrients are generally not recommended. Also, if a tree has produced growth that is healthy and typical of its species over time, the need for fertilization is not justified.

Trees located in good growing conditions but producing a poor growth rate over time may benefit from fertilization.

Other caveats

Fertilizing trees under stress isn’t generally recommended. It’s better if the tree’s resources are used to defend it against insects and diseases and for root regrowth, rather than using up stored sugars to produce new leaves. Other trees and shrubs that should not be fertilized include newly planted specimens and those with root damage from recent trenching or construction. The root systems need time to re-establish before fertilizers are applied.

For mid-spring and late fall applications, there’s a fine line when it comes to fertilizing specimens under stress. Yes, applied nutrients can increase resistance to stressors; however, if the stressors are causing the tree to decline, it’s best to avoid fertilization until the tree recovers.

Also, a specimen may not need fertilizer if an application has been made and the tree still looks thin or produces inadequate growth. In other words, if your fertilizer application doesn’t produce the results you were looking for, investigate to determine the factors that are affecting the tree’s health.

Expanded mulch areas provide enhanced growing areas for tree roots.

Alternative treatments

There are some other treatments that can produce a similar effect on tree health as fertilization.

Aeration – This opens up compacted soils, increasing the movement of oxygen into the pore spaces and facilitating greater water infiltration. Many specimens struggle because the roots cannot expand laterally to support the needs of the tree.

Expanded mulch area – Mulch, placed in a manner that simulates Mother Nature, could be the ticket to improved tree health. Expanded mulch areas offer the additional benefits of moisture retention and weed suppression.

Compost application – Depending on the landscape situation, thin applications of compost will provide a dose of slow-release nutrients. The key is thin, not more than 1/3 inch deep. Compost applications are best following lawn aeration in landscapes where a tree is in the midst of a sward of turfgrass.

John C. Fech, an ISA certified arborist and certified tree risk assessor at the University of Nebraska-Lincoln, is a contributing writer to Tree Services.

(Article courtesy of Tree Services Magazine:

Summer Safety: How to Beat the Heat

Summer Safety: How to beat the heat and keep your crew safe when the mercury rises

By Tony Tresselt

Summer is often the busiest season for production tree workers. Dormant season’s end, summer storms and active insect and pathogen populations all add to the pace of tree care operations. Many tree care companies depend on the summer months to sustain them through the rest of the year. For most it is a make-it-or-break-it time. Therefore, a successful summer season is important.

Just as any tree job has specific concerns, so too does the summer tree season. Never is safety and efficiency more important than when workloads increase and the difference between a good year and a bad one may boil down to the activities of a few short months.

Photos courtesy of Tony Tresselt .

Safe work practices are always necessary and cost-effective. However, each season brings its own challenges. Tree workers can do many things to stay safe and productive this summer; we’ll look at three. By avoiding heat injuries, watching out for summertime pests, and ensuring proper equipment maintenance, this summer can be safe and successful.

How about this heat?

For many parts of the country, summer months mean increased temperatures and/or humidity. Heat injury, from mild dehydration to outright heat stroke, is a constant worry. Review the additional hazards of working in high heat and humidity during site safety briefings. Be sure the job plan includes breaks and that plenty of cool, clean water is available.

Focus a longer safety meeting on recognizing heat injuries in yourself and other crew members. Look at abatement strategies and proper treatment. If caught early, heat injuries can often be lessened or entirely avoided. Should a crew member become incapacitated by the heat, be sure he receives proper medical care promptly.

Heat injuries are serious and must be acted on accordingly. Just because there is no blood and gore does not mean a crew member may not need quick, thorough medical care. Just as with so many things, an ounce of prevention is worth a pound of cure.

Learn to identify poisonous plants and inspect carefully for all manner of pests before working.


Warmer weather also means that many other forms of life are more active. Bees, wasps and other stinging insects can be hidden in thick tree canopies or trunk cavities. In early summer, wildlife may be breeding or already have young broods. Beware of animals that may be more aggressive because of these cycles. Animals and birds are also more likely to be in nests and dens and may not appreciate your daytime visit to their lofty perches.

Be thorough in your risk assessments and inspect for evidence of wildlife before starting work. If crew members have any allergies, be sure the entire crew is aware and knows what to do should an incident occur. Make ready any necessary medications or other forms of treatment, and be trained and ready to use them when needed.

Not all pests are four-legged. Be aware of and able to identify poisonous plants. Even a mild allergic reaction to plants can cause discomfort and add to fatigue and frustration at the end of a long day. Be sure crew members can identify the major reaction-causing plants in your area, and develop a plan to avoid the risk or minimize the exposure.

Equipment woes

Production tree care is dusty, dirty work any time of year. Add high temperatures and longer hours and summer work takes its toll on workers and equipment alike. Be sure all motorized equipment is serviced and running well. The frustration of malfunctioning equipment and long, hot days can be hazardous, if not fatal.

Make sure the crew has plenty of cool, clean water to drink on hot days.

Sharpen saws and brush chippers regularly. Dull tools are no fun and can be dangerous. Be sure to clean radiators and cooling fins often. A clogged radiator might not make a difference when the temps are below freezing, but it can ruin efficiency on a warm day, not to mention the time lost and repair cost of a cracked block or other damage.

Saw and equipment maintenance is even more important in the busy season.

Mechanics will tell you they get more service calls on days with extreme temperatures. Make sure tires are at the correct pressure and in good shape. Tighten lug nuts and check brakes regularly. Top off fluids as necessary. Machinery without proper fluid levels has to work harder to do the same job. Low fluid levels usually mean higher working temps, and greater and quicker wear. What you may squeak by with on a mild day will catch up with you as time and temperature increase.

Be sure to store fuel and oils in shaded or cooler areas, as direct sunlight can cause unvented cans and/or storage bins to become pressurized and/or explosive. Saws and other gas equipment are slower to cool, so extra care when refueling is wise. Clean up spills promptly and use good judgment when filling hot equipment on hot days.

The summer season can be a great time to get a lot of work completed. However, increased workloads and temperatures, active hazardous pests and plants, as well as more demanding equipment usage can all add to the stress of a busy season. Make sure that safety briefings reflect these added concerns. Prepare workers and equipment alike with the tools and knowledge necessary to deal with the summer heat. Plan your work and work your plan. This becomes especially important as the summer months settle upon us.

 Tony Tresselt is a climber, trainer, writer and student of arboriculture associated with North American Training Solutions, Arboriculture Canada Training and Education and Arborist Enterprises.
(Article courtesy of Tree Services Magazine:

Tree Health: Pesticide Safety

By John C. Fech

Determining the need for pesticide application is a good first step.

(Photo court esy of James Kalisch, UNL.)

There are many critical issues in the tree care industry, from invasive pests to the implementation of pest monitoring, from training new workers to marketing to new customers, and from tree risk assessment to tree establishment. Human nature being what it is, our interests are not equal amongst them. Unfortunately, although it’s of central importance to tree care workers and arborists, pesticide safety is one area where there is a low level of interest. As such, it is easily overlooked, and in some cases downright ignored. There are several facets of pesticide safety, and they should be considered in the daily course of operations.

Safety during selection

When choosing amongst all the available products, consider those that require less exposure during application, mixing and storage. Straightforward discussions with product distributors and university extension faculty as well as a thorough reading of the label will provide information about which products are associated with the various types of protective gear and equipment. When the decision is being made, selecting product x, which requires less exposure, over product y is a type of preemptive action that can prevent potential problems before the product is put in the spray tank.

In addition to exposure, consider the toxicity level of the product. The three signal words are good clues for this factor. Products with the signal word “caution” are lower in toxicity; those with the signal word “warning” are moderately toxic; and those marked “danger” are highly toxic. For example, soaps and oils are generally safer than other pesticides since they are lower in toxicity and as such are marked with the signal word “caution.” The LD50, (lethal dose to kill 50 percent of the test population) is another indicator of potential risk from the product.

Bark treatments can be very effective as targeted applications, but can produce unacceptable drift. (Photo court esy of James Kalisch, UNL.)

Safety during mixing

Your eyes, hands, face and, dare I say, the organs below the belt need to be protected. When in doubt, focus on the protective gear needed when mixing the product with water, as this is when you’re dealing with the product in its most concentrated form and therefore poses the most risk. At a minimum, a face shield, rubber apron, nitrile gloves and rubber boots should be worn.

Typically, eye and skin exposure is the most common when applying or handling (loading, reorganizing, reading labels, etc.) pesticides. It’s also the easiest route of entry to prevent. Chemical-resistant gloves that cover the hand and forearm provide very good protection. Unlined gloves made of nitrile, neoprene or butyl rubber are excellent choices. Fortunately, quality gloves are not expensive. Depending on the frequency of use, manufacturer and product choice, gloves may last from a day to a week to a month.

Safety during application

Whether the application is a spray, injection or basal drench, appropriate footwear is commonly overlooked when applying or handling pesticides. Boots can either prevent or promote pesticide poisoning. Leather boots, such as work boots or cowboy boots, can easily absorb pesticide products. The harm can be initial and long term. If a liquid product is spilled on leather boots, it’s possible for the pesticide to be absorbed as it soaks through the boot. If this occurs, immediately consult the pesticide label for information on how to reduce harm to your body. Better yet, read the label before mixing or applying the pesticide so you know this information beforehand and can act immediately.

Storage facilities should be clean and well organized.

(Photo court esy of Clyde Ogg, UNL)

Chronic or long-term pesticide poisoning can result from small amounts of product that are absorbed with each application. The product is likely to be retained in the leather, creating an unacceptable risk to the applicator. Chemical-resistant boots or shoe coverings should be worn. Use the pesticide label as a guide when choosing footwear. Generally, rubber is considered to be a better material for preventing pesticide absorption than leather.

For eye protection, consider the wide array of goggles on the market. Most are designed to fit over eyeglasses. Some have shielded vents that allow for reduced fogging and heat buildup. All are designed to prevent splash and particle drift during application. The bottom line: eyewear is important. In many application scenarios, the product mist is quite fine and may be unnoticeable to the applicator.

In addition, for specifics on rates, water pH, reentry time, need for surfactants and compatibility with other pest control agents, as well as what personal protective equipment (PPE) may be required, read the pesticide label thoroughly before use. That’s where you’ll find this and other valuable information.

Safety after application

Quick, think of three things that you don’t use your hands to do … kind of hard to think of any, let alone three. Even after applying a pesticide with nitrile rubber gloves, get into the routine of washing your hands. The rule is to do so three times using hot water, followed by a good rinsing. Of course, this is to be done before using the restroom, smoking, eating or any other activity where you might touch an unprotected part of the body or material that might absorb or hold pesticide residue, such as a ball cap or steering wheel.

Proximity to streets and sidewalks is always a concern.

(Photo courtesy of John C. Fech)

Proper laundering of pesticide-contaminated clothing is essential for applicator safety. The first consideration is to deem any clothing worn while at work as contaminated and in need of washing. It’s important to always wash pesticide-contaminated clothing immediately after use (don’t let it lay in a heap for a week or leave it in your hamper, and be sure to separate it from other laundry) and start by prerinsing. Research at several land-grant universities has indicated that using hot water, heavy-duty liquid detergents and the maximum water level for the washing machine are most effective at removing pesticide residues from clothing.

Just as with rinsing spray tanks and backpack sprayers, removing possible residues from the washing machine is important. When the wash cycle is completed, run the empty washer through a complete cycle with detergent and hot water to clean the machine.

Storage of unused pesticides is another facet of pesticide safety. Certain products may require unique conditions, so storage location/facilities may vary, but all should be well lit so it’s easy to read the label and distinguish similarly looking products from each other.

Generally, favorable environments for pesticide storage maintain a temperature of 60 to 65 degrees Fahrenheit, have a low relative humidity, are out of direct sunlight, and are arranged in such a way that access is easy and open and allows for quick observation to see if products are missing, bags are torn or put away incorrectly. A good storage unit will be able to be securely locked and posted as a pesticide storage area, will keep pesticide products dry, is fire resistant, and contains a well-functioning exhaust fan for ventilation. It’s wise to design the facility to make it adaptable and allow room for expansion. To create good storage conditions, follow these rules: the area must be stable, easy to use, and accommodate the products you use.

The author is a horticulturist and certified arborist located in Omaha, Neb.

(Article courtesy of Tree Services Magazine:

Tree Health: Fighting Fungus

The history of the site is telling; imagine inspecting this tree 10 years in the future and not knowing that the roots were cut early on in the tree’s life.
Photos by John C. Fech, UNL, unless otherwise noted.


Fighting Fungus … a daunting magazine article title and overall endeavor indeed. However, it’s a battle worth waging, regardless of the difficulty factor. Though a bit on the trite side, the phrase attributed to Theodore Roosevelt, “Nothing in the world is worth having or worth doing unless it means effort, pain, difficulty,” is often shortened and modified to “nothing worth having is easy” and certainly applies in this case.

Though it’s sometimes a difficult task, the challenge of keeping trees healthy and fungus-free is best accomplished through a multifaceted approach. Identification, monitoring, evaluation of methodologies, preventative measures and conducive growing conditions are some of the more important considerations.

Regular inspection

Whether you call it monitoring, scouting or inspection, a regular close-up look at trees on a customer’s property is a tried and true part of integrated pest management and integral to fighting fungus. If the goal is to keep fungi at bay, you need to know when and where they are attacking, or at least present. If you don’t look, there is no real way to know.

So, what is “regular?” In terms of tree inspection, regular means frequent and thorough. Since many fungi that cause problems for trees are active in the spring, regular inspection should be more frequent in the spring than in the summer or fall. As a result, symptoms are noticed sooner and there is more time left in the year to treat. When maladies are noted in the fall, the action is more a matter of notation and recommendation for follow-up applications in spring, especially if the treatment threshold has been surpassed.

The often underutilized part of inspection is profit. In short, do it, do it often and make money from it. When one considers the investment of time, training and effort that a qualified tree worker puts into their career, it needs to pay off in one way or another. If certification through the International Society of Arboriculture (ISA) or a state arborists association has been achieved, the knowledge, skill and experience must be factored into the equation. After all, the ISA doesn’t hand out certification to just anyone.

A good way to be sure that inspections are an integral part of the income stream is to explain to customers that inspections are just as important as spray applications. Depending on where your customers live, it may be wise to equate monitoring for insects with a fall furnace checkup or a spring air conditioning service. No one wants to suffer through a cold winter or hot summer without relief. If the temperature outside is the same as it is inside in summer or winter, then the equipment is broken or it’s an anomaly.

In terms of the number of site inspections, it’s dependent on the disease susceptibility of the species on the property and the localized conditions. For example, if a given customer has a ginkgo, a red oak and an Osage orange tree, they would need fewer inspections per season than one with a crabapple, an Austrian pine and a cottonwood; the former are generally considered to be disease-resistant trees, while the latter are more likely to develop fungal problems from time to time. Likewise, since many fungal pathogens require high moisture content on foliage to develop and infect a tree, properties with low air flow across leaves are more likely to be conducive to ongoing problems than ones with good air circulation. These factors should be made clear to a customer when pitching the service of regular inspections.


Determination in the endeavor of fighting fungus on landscape trees is important from two perspectives: determination in the sense of persistence, and determination in the sense of identification.

First, identification. Even after years and years of diagnosing unknown maladies, determining which exact causal agent is responsible for the symptoms that have been produced on a tree can be challenging. How can you fight something if you don’t know what it is?

Determination, or diagnosis, can start in many ways. My preference is to begin with known maladies of the tree species. For example, crabapple has a long history of susceptibility to powdery mildew, apple scab, fire blight and cedar apple rust. If the customer has a crabapple, your first step is to get to know the symptoms of these diseases and compare the current presentation of the leaves, stems and trunk to those established characteristics.

A good second step is to consider the micro and macroclimates of the property. When I was starting out in horticulture and arboriculture, a wise arborist did me the favor of teaching me how to walk the entire property, as well as the adjacent lots and neighboring areas, looking for clues as to what might be influencing the current situation. He taught me to carry a clipboard and use it to make notes on wind patterns, sunlight penetration, coverage of the root system with impervious surfaces, and competition from other species.

Knowing the history of a site is useful as well. Interviewing the owner and possibly the neighbors about recent herbicide applications to the turf, soil modifications, utility work, and the performance of other woody species can be helpful in determining what’s causing the tree’s health to decline.

Leaf scorch on dogwood underscores the need for regular inspection.

It’s not all about fungus. To eliminate possible nonliving/abiotic organisms as causal agents, items important to learn to distinguish between fungus and non-fungus. In fact, one of the little known secrets of determination is that less than half of the causes of tree problems are related to fungal or bacterial organisms. Overwatering, lack of separation of turf and trees, planting errors and mower blight are just some of the non-fungal inputs that can cause trees to suffer.

Next, persistence. Because it’s not easy, sometimes it just takes time to get it right. After a good first look, take the time to check the resources on your bookshelf. Go online and type in phrases such as “maple diseases in the Northwest” or “ash problems” into Google Images or Yahoo Image Search. You’ll be amazed at what you find. Talk to other service technicians in your company and university extension faculty about possible causes.

As you move through the process, stay in communication with the client. They’ll appreciate your thoroughness and your persistence.


Whether you’re delivering a joke at a dinner party or buying an airline ticket, timing is undeniably crucial. The same is true when fighting fungus on broadleaf and evergreen trees. Too early or too late with inspection, determination or treatment is not going to cut it. Correct timing is important for each of these factors. The timing needs to be right for inspection in order to be ahead of the curve, to read and react in relation to the clues given by the plant. The determination of the causal agent needs to be on track, and needs to be done in advance of the treatment application if one is necessary. Treatments applied before or after the vulnerable stage of the fungus or plant part are simply not effective and should be viewed as a disservice to the customer.

Each is important on its own, but the correct timing of all three needs to occur in order to conquer fungus. With time, training and experience, as well as due consideration of the key elements presented in this article – regular inspection, species vulnerability and characteristics, the history of the site, differentiation between abiotic and biotic causes, persistence and timing – the fight can be won.

John C. Fech is an ISA Certified Arborist, PNW ISA Certified Tree Risk Assessor at the University of Nebraska-Lincoln and a frequent contributor.

(Article courtesy of Tree Services Magazine:

Emerald Ash Borer – Symptoms and Treatment

Emerald Ash Borer

(Courtesy of  USDA Animal & Plant Health Inspection Services) 

 Symptoms and Treatment: 

Adult EAB

Although you can’t always spot it, the beetle may live in cut wood such as firewood. You can help stop the beetle by not moving firewood. Moving firewood can spread the beetle, its larvae and its eggs to healthy trees. Burn your firewood where you buy it.


Adult beetles are most active during the summer and early fall. If you see the beetle or any signs of infestation, you need to report it immediately. (Contact your local U.S. Department of Agriculture Office.) During the late summer, fall and winter months, the beetle’s larvae tunnel deep into the trees they infest.

The Signs:
 Since the beetle is difficult to spot, you can look for signs of infestation.


Canopy Dieback
Canopy Dieback

Canopy dieback begins at the top of the tree and progresses throughout the year until the tree is bare.



Epicormic Shoots:


Sprouts grow from roots and trunk.

Bark Splitting:

 Vertical bark splits expose S-shaped galleries beneath the bark.


 S-shaped Galleries and D-shaped Exit Holes:

 Galleries under the bark reveal the back and forth feeding pattern of the EAB larvae.  Adults emerge from D-shaped exit holes.



 The following insecticides for professional use have been shown to be effective against the Emerald Ash-Borer either as a soil drench or as a tree injectible. (Read the full report of insecticide treatment and their rate of effectiveness by following the link below.)


1. Merit® (75WP, 75WSP, 2F) (Imidacloprid) – Use as soil injection or drench. Mid-fall and/or mid-to late spring.  Merit® also is available as a trunk injectible.


 2. XytectTM (2F, 75WSP) (Imidacloprid) – Soil injection or drench Mid-fall and/or mid-to late spring.


3. IMA-jet® (Imidacloprid) – Trunk injection Early May to mid-June.


4. Imicide® (Imidacloprid) -  Trunk injection Early May to mid-June.


5. TREE-ägeTM (Emamectin benzoate) -  Trunk injection Early May to mid-June. While relatively expensive, this product has shown to be the most effective chemical  treatment to combat the Emerald Ash Borer according to studies by the Michigan State University and others.

6. Inject-A-Cide B® (Bidrin®) -  Trunk injection Early May to mid-June.


*Homeowner Use – Bayer Advanced Tree & Shrub Insect Control -(Imidacloprid) Soil drench – Mid-fall or mid-to late spring.

Rigging Pulleys and Blocks-Part I

Tools & Techniques:
Pulleys and Blocks

When Friction is Not a Friend

By Michael Tain

CMI Rescue Pulley

(A CMI rescue pulley in support of a static load. Note the lack of a bushing for sling attachment, thus requiring the use of a connecting link, and the thin side plates with sharp edges. Photos by Michael Tain.)

Pulleys and blocks play a major role in the modern tree climber’s bag of tricks, often performing vital functions in the most basic of tasks, such as hitch advancement, or the most complex, as in a multiple system rigging required tree removal. Regardless of application, the primary function of a pulley or block is to reduce friction as much as is possible within the given situation.

With the various types of pulleys and blocks available to tree crews today there’s one for almost every application, but along with the benefit of choice comes the burden of knowledge. The wrong block or pulley used in the wrong situation can be catastrophic for the pulley, the line, the tree and even the crew members in the path of destruction. A basic knowledge of some of the applications, suitability and safety concerns of these useful tools will go a long way towards ensuring that crews not only use them most efficiently, but also as safely as possible.


Pulleys and blocks perform the same basic function: providing a sheave or surface of some sort that reduces friction as much as possible on a running rope. In many industries the terms “block” or “pulley” mean the same piece of gear, this is not the case in tree care applications. While both perform the same basic function – and can even work interchangeably in the short term – the wrong choice can have disastrous results, especially when large woody debris at a height is involved.

Blocks, but not for the alphabet

The term arborist block is used to refer to a block/pulley designed to deal with the heavy loads and extreme forces of dynamic rigging situations. While there are a variety of designs and styles available, they will have several basic components in common: a bushing, a sheave and cheek plates.

Bushing, not bush league

The bushing in an arborist block is intended for sling attachment and will have some form of locking mechanism to ensure it does not release mid-load. Available mechanisms include spring locks and captured bushings with screw locks. Arborists in the market would be best served to purchase captured bushings regardless of locking mechanisms, as attempting to find a bushing dropped from 90 feet into a pile of pin oak brush can be a bit challenging. Whichever type of locking mechanism the bushing has, the user should be certain it’s correctly locked and secured after every load, or catastrophe may rear its ugly head.

As mentioned previously, the bushing – typically the smaller diameter of the two block ends – is intended for sling attachment, with the sling then attached to the tree with an appropriate hitch such as the cow hitch with a better half. The use of connecting links, even large heavy-duty rigging carabiners, from the sling around the bushing is a poor idea, as the possibility of side or cross loading is highly likely in dynamic rigging situations, and the metal-on-metal contact between connecting link and bushing quickly degrades the strength of both.

ISC Block

(An ISC spring-lock aluminum arborist block. Note the spring-lock captured bushing for sling attachment and the thick side plates with rounded edges, making it appropriate for more dynamic loading.)

(Article courtesy of Tree Services Magazine:

Rigging Pulleys and Blocks-Part II

Tools & Techniques:
Pulleys and Blocks

When Friction is Not a Friend

By Michael Tain

Sheave, not sleeve

The surface of an arborist block that the line is intended to run over is called a sheave, and it’s typically the larger diameter of the two block ends. This sheave should turn freely, minimizing the amount of friction the rope experiences when running over/around it.

Bend radius is a concept that must be understood when matching arborist blocks with rigging lines. In short, the sharper the bend in a rope passing over or around any object, the more strength the rope will lose. A bend radius of 8 to 1 is the most advantageous for minimizing strength loss, though a radius of 4 to 1 is acceptable in arborist rigging situations with lines of braided construction. As an example, a .5-inch rigging line should be used with a block with a 4-inch-diameter sheave for optimal strength retention, though a sheave diameter of 2 inches would be minimally acceptable.

Cheeks like a chipmunk

The cheek plates of a well-designed quality arborist block are thick and extend beyond the bushing/sheave with somewhat rounded edges. This thickness helps provide the strength required for enduring the loads and forces involved multiple times in tree removal rigging.

In addition, the extension of the cheek plates helps ensure that the sling remains in proper contact with the bushing, and the rigging line in proper contact with the sheave, while rounded edges help minimize rope damage should the line get trapped or run between the edge and the tree.

Pulleys aren’t bullies

Pulleys, as mentioned previously, are not the same piece of gear as a block in the tree industry. They should, perhaps, be thought of as the slender, more sensitive, but still quite useful, cousin of the big, burly arborist block.

While they do have the sheave of an arborist block, they lack the bushing for sling attachment, typically having an opening of some sort for the attachment of a connecting link. This particular lack is what prevents the safe use of pulleys in rigging applications involving dynamic loads and forces. The use of a connecting link through the opening provided can lead to cross or side loading in these situations. Given enough force or large enough load, the connecting link can tear entirely through the pulley’s thin, non-chipmunk like cheek plates, sending the load and pulley on a high-speed one-way trip to the unsuspecting branch manager.

Arborist Block

(An arborist block-note the bushing-being used as the traveler in a balance slide line rigging system.)

An attempt to avoid the use of a connecting link by girth hitching the sling through the pulley’s provided opening is also problematic and unsafe, and can lead to bent and mangled cheek plates or slings severed by the sharp edges present in most pulleys.

There are a wide variety of pulleys available to modern arborists, and far too many configurations to all be discussed here. The few listed below give a good introduction to some of their appropriate applications.

Fixed, no not that way, sides – Pulleys with fixed sides or cheek plates typically, though not always, have a distance between the two sides equal to the thickness of the sheave. This allows their effective use in a number of applications, but common uses include as a fair lead for climbing hitches and as the traveler in a slide line system.

Multiple sheaves – Pulleys with more than one sheave are readily available and are particularly useful in the construction of mechanical advantage systems to provide lifting or pulling force greater than the input force.

Prusik minding – These pulleys are shaped in such a way that the cheek plates of the pulley, when properly used and configured, actually “mind,” or advance, a prusik or other hitch when it reaches the pulley. This feature is exceptionally useful when moving or advancing a load when it cannot be allowed to slip or travel backwards, or when attempting to apply gradual, constant force in a mechanical advantage system.

More attachment points – Pulleys, typically of a smaller size, are readily available with multiple attachment points that provide uses in both rigging and climbing situations that are only limited by the imagination of the user and the strength of the chosen pulley.

General rigging – While a pulley’s lack of bushings and more slender construction preclude their use in dynamic rigging situations, they are highly applicable and safe in non-dynamic applications, such as lifting, pulling or redirecting, as long as their safe working load is not exceeded.

Spider leg balancing a load

A spider leg used to balance a load, one of the rigging applications that is much easier to control readily through the use of blocks and pulleys.

Loads, briefly

Terms such as breaking strength, safe working load and working load limit are a discussion all to themselves, but prospective block and pulley users should be aware of the strengths of their chosen devices and how they will function within the chosen application.

In short, a listed breaking strength is just that, the one-time load the pulley or block should take before breaking. Multiple uses will incrementally reduce that breaking strength, and multiple uses near the maximum strength of the block or pulley will reduce its strength even more severely, thus care and caution must be used when employing rigging systems and the blocks/pulleys within them.

Prusik mindng pulleys

(Multiple sheaves prusik minding pulleys being used in a mechanical advantage system.)

Pulleys and blocks can increase the safety and efficiency of both individual climbers and entire tree crews, but only if they are being used appropriately and correctly. The basic knowledge, descriptions and limitations discussed here are a good first step towards helping tree care professionals use blocks and pulleys to battle friction in the pursuit of safe, efficient tree care.

(Michael (House) Tain is a contract climber, splicer, educator and writer associated with North American Training Solutions/Arbor Canada Training and Education, currently located in Lancaster, Ky.)

(Article courtesy of Tree Services Magazine:

Maintaining Your Climbing Equipment

Maintenance Matters

Maintaining your climbing equipment is imperative to staying safe aloft
By Anthony Tresselt

(All life support carabiners should be marked with their ratings and the markings should be legible.)
(Photos courtesy of Anthony Tresselt unless otherwise noted.)

As with any type of skilled labor, high-quality tools and equipment are necessary for safe production tree climbing. As important as knowing how to use these tools and equipment can be, keeping them functioning properly, inspected for signs of wear, and knowing when to retire them is equally important. Tools can only perform as designed if they work and are used as intended. Just as a chain saw must be tuned, fueled and sharpened for effective cutting, climbing gear must be properly maintained. While a malfunctioning saw could be  a safety concern, it is more likely to be a frustrating nuisance. However, when it comes to life support equipment,  the results of poor maintenance are guaranteed to be much more severe.

Through knowledge, regular inspection and maintenance, climbing gear can be kept in tip-top shape, performing safely and as designed for many jobs today, tomorrow and many days to come.

Instruction manuals

Realistically, we can only discuss general guidelines. The vast amount of gear available to the modern tree climber coupled with the multifaceted way it can and is deployed would lead to a tome of epic proportions in trying to cover every detail. However, there are similarities and processes that can be applied universally across the range of climbing equipment.

Furthermore, there are instructions! Equipment manufacturers provide detailed instructions for the use and upkeep of all gear. These may come with the equipment or tool or can be obtained online in a digital format. Keeping a file of these for reference is a great first step in proper maintenance. Use these as the guidelines and training tools for which purpose they were developed.


Much like the high-tech industry, climbing hardware refers to the infrastructure items on which we build our systems. These are the ascenders, connecting links, adjusters and anchor points we use to get up, go to work and get down safely. Start by checking for ratings and markings. Most life support equipment is constructed of metal. As such, it will have ratings etched, stamped or molded into it. Find these and be sure they are still legible. Even properly rated equipment with unreadable marking can be a bone of contention for insurance and/or OSHA inspectors. More importantly for the working arborist, it is a good indicator of wear and use.

For instance, a carabiner with a laser-etched rating that is worn off may be a good field guide as to the amount of metal that has been worn away. This is not to say that the carabiner has an immediate chance of failure. However, if you have properly used a carabiner to the point that the ratings, whether etched or molded into it, have worn off, then you have used that tool for a while and you should consider replacing it.

Also note how distributed the wear is over the entire body of the tool. Back to our carabiner example: If the center of the spine is worn or nicked up but the rest of the carabiner looks relatively new, there may be a gear interface issue.

Clean equipment is happy equipment! Clean hardware/equipment also functions as designed. In general, soap and water will suffice for cleaning climbing hardware. You can use compressed air, but be careful not to force dirt or tiny debris further into moving parts and mechanisms. Dry lubricants, such as graphite or Teflon, will keep dust from clinging to moving parts. However, the solvent abilities of other oil-based lubricants may also be helpful.


In tree climbing, nothing takes abuse quite like ropes and other cordage items. If they get wet, dry thoroughly as soon as possible. Protect them from excessive wear by using friction-management devices. Inspect ropes regularly and retire if any doubt exists as to the strength or integrity. Missing or frayed lockstitching on splices can be repaired. Chafe guards, by design, will wear and should be rotated or replaced as necessary.

Slings affixed to metal objects without the ability to rotate freely (i.e. girth hitched) should be rotated regularly to check for wear to both items. This also allows for faster, more thorough drying. Slings, hitch cordage, climbing lines and other cordage-based equipment can be washed.

Specialized rope washers are available and may be a great alternative. However, in many cases no specialized equipment is necessary. Disassemble gear and/or systems as appropriate. Longer lengths should be chain knotted or placed in a mesh bag. Use a machine without a central spindle. The front-loading industrial machines at your local Laundromat work well. Use warm to cold water with a mild detergent absent of fabric softener and your ropes will have a new lease on life. Wash as often as necessary.

(A series of slipknots on a four-parted rope make it ready for the front-loading washer and a new lease on life.)


Keep leather climbing saddle components supple and oiled with an appropriate leather treatment. This helps keep leather from cracking and makes drying it out easier, not to mention providing a more comfortable fit.

Lubricate buckles for smooth, proper function. Check shackles for tightness and apply thread- locking liquids as the manufacturer recommends. A small dab of fingernail polish applied to the screw head and the body of the shackle will allow you to detect movement in the field. Reapply the thread locker and marking as necessary.

Check your bridge and replace on a regular basis. Use materials recommended or provided by the harness maker. Not all cordages and webbing are created equal, and some are downright poor choices for a harness bridge. Customizability and ease of replacement are key features of rope and webbing bridge harnesses. Use these features to your benefit, and maintain the bridge with inspection, cleaning and regular replacement.

(Using fingernail polish on the head of shackles allows the climber to easily determine if they have become loose in the field.)


We’ve looked at a few maintenance issues and procedures for climbing equipment. Like all tools, from your chain saw to your brush chipper to your truck, climbing equipment is subject to wear and tear even through proper use. Keep all your climbing tools in good working order through cleaning, inspecting, lubricating and replacing when necessary. Follow the manufacturer’s recommendations and inquire if you are unclear. Keep manuals and literature provided with all equipment in an organized file and refer to it as necessary. This is also an excellent place to document your inspection process in a timely manner as determined by your usage patterns.

Take care of your equipment with proper maintenance and it will take care of you through a lifetime of reliable function.

(Tony Tresselt is a climber, trainer, writer and student of arboriculture associated with North American Training Solutions, Arboriculture Canada Training and Education and Arborist Enterprises. Follow his exploits or get in touch at his blog or his website Gravitational

(Article courtesy of Tree Services Magazine:

Tree Health: Winter Weather Woes

Keeping customers happy while dealing with snow and ice damage

By John C. Fech

(Rabbit browsing is common in winters with extended snow cover.
Photos by John C. Fech, UNL)

There are many ways to perceive or view winter damage to trees. One is to deny it, to say to yourself or others “Oh, it’s not really that bad,” and find ways to deflect attention to the injury. Another is to accept it, to realize that it is what it is, or aquí es en Español. A third is to fight it, to dig right in and think of ways to recover from it, or prevent it in the future.

Which of these works best? While this question can be difficult to answer, it’s helpful to understand the thought processes behind the feelings associated with the damage. In most scenarios, a combination of the latter two is usually most reasonable. After all, tree care providers are not in control of all the factors that affect trees, and as such it’s illogical to assume that as a result of your efforts nothing bad will ever happen again.

Consequences of damage

There are basic rules, or tenets, that are part of our culture and hard to argue with. The first two: There are only two things certain in life, death and taxes; and supply and demand drives our economy. The third: cause and effect. In the context of winter damage, the cause is usually unknown, at least in the short run, and the effects can be varied.

The most obvious effect is the injury to a woody plant. Many trees are quite valuable to clients in terms of aesthetics, temperature modification and property value; their demise is usually problematic.

If the damage is severe, one consequence may be the loss of a customer, even though the tree care company had nothing to do with the injury. Clients can be fickle and use the damage as a reason to switch to another company or discontinue tree care altogether.

Winter construction projects can cause damage that is difficult for trees to recover from. The loss of a good reputation is also a possibility. Losing a positive reputation amongst the customer base, other tree care providers, city officials and suppliers can have long-term negative effects on a company, especially if it’s a small company and word-of-mouth is the primary advertising method.

Regardless of which of the three may be encountered, none are desirable. On the other hand, dealing with damage in a sound and responsive manner may increase your standing with the customer and positively reinforce the business relationship. Therefore, proceeding in a logical and straightforward manner is a worthy endeavor.

(Corrugated PVC collars are effective in preventing damage from mice and other critter)

Seven steps

As with any of the problems that we encounter in life, a certain level of acceptance is healthy. It matters not whether you’re considering which eldercare facility is best for your parents or how to invest for retirement, a step-by-step process is a good course of action. The following seven steps, courtesy of Steven Rodie, ASLA, University of Nebraska-Lincoln, are an effective guiding procedure in terms of diagnosing winter damage and devising a healthy response for the customer.

1 Accept the situation

2 Analyze facts and feelings

3 Define goals and objectives

4 Generate ideas to achieve goals and objectives

5 Select best ideas or combination of ideas

6 Implement

7 Evaluate; start over; never finished

Accept the situation. This requires work by both the tree care provider and the customer. Sure, it’s different work for each party in that the worker/owner/arborist usually sees the tree as a valuable part of nature and possible work for hire, while the owner will be thinking more locally and property specific. In the end, it is what it is; it happened.

Analyze facts and feelings. The fact may be that a large limb has fallen to the ground or is hanging on the house, or the entire tree has turned brown and needs to be dealt with. The owner often sees these facts, but combines the actual occurrence with the hurt or loss of a valuable asset and needs to process the feeling in their own mind. It’s best to keep this in mind when talking with the customer and give them some time to work through their feelings, especially if it is a memorial or historical tree.

Define goals and objectives. Depending on the severity of the injury, it is helpful to revisit the importance and purpose of the damaged tree. If the tree in question was an undesirable volunteer that sprouted 2 feet from the foundation, then this may be a blessing rather than a problem. Damage often provides an opportunity to rethink why each tree is in place on a given property in terms of the benefits it provides and the effort that is required for its care.

(Warming and cooling of the bark in winter can cause damage to the cambium)

Generate ideas to achieve goals and objectives. Recovering from winter injury is usually easier if several ideas to move forward in a responsible manner are generated. These should be directly related to the goals and objectives for each tree as well as the property as a whole. As a tree care provider, it’s wise to generate some ideas based on your experience with other clients and share them with the customer, keeping in mind that they will likely have some ideas of their own.

Select best ideas or combination of ideas.Selection of “best” ideas is a highly subjective process. After the ideas are presented to the customer, unless their choice is a poor arboricultural practice such as topping a winter damaged tree or removing most of the lower limbs (lions-tailing), deferring to their choice is probably the best course of action. Once you have presented several reasonable and sound options, remember that it’s their tree and they have the right to choose their preferred course of action.

Once the choice has been made it’s time to implement the action. Some actions should be implemented immediately; for example removing a fallen limb. For some damage the required actions may be part of a longer-term plan. If this is the case, devise a simple project plan or punch list detailing the work and the time frame to get it done, and present it to the customer in a walk and talk around the property.

Evaluate; start over; never finished. After the implementation of the plan, it’s wise to evaluate how well the action accomplished the goals and objectives for the trees on the property. Did the removal leave an unacceptably large gap in the tree line? Does dead wood remain in the tree that needs to be removed? Would application of mulch around the remaining specimens improve their function and appearance? Have defects such as cracks, codominant leaders or decay developed since the implementation? All of these are important questions to ask and discuss with the customer. Following the discussion, it may be necessary to start over, or implement additional actions. In terms of good tree care, the use of best management practices is never finished, at least as long as the tree is in the ground on the property.

(Winter storms, especially storms in late winter, can be responsible for damage)

Diagnosing damage

For maladies that occur in winter, a good starting point is to attempt to distinguish between winter damage and other causes. This may be easier for existing clients than for new ones, in that notes and comments made in the records for each day’s work or routine inspection can provide a basis for comparison. As each are considered, the “cause and recovery” approach should be utilized.

The most common causes of winter damage are mice and other critters, winter construction projects, sunscald, desiccation, winter storms and miscellaneous forces. Depending on the area of the country and the length of time trees are covered with ice and snow and the soil is frozen, lots of damage can happen over the winter, most of which neither the tree care worker/arborist or the property owner has any control over. In certain instances it may be coincidental and could have just as easily occurred in the summer.

Miscellaneous causes can also be classified as “additive” causes, where slope, inadequate room for shoots and roots to grow, impervious soils, cold temperature stress from fluctuating winter temperatures, or any combination thereof can cause trees to fail.

(John C. Fech is an ISA Certified Arborist, PNW ISA Certified Tree Risk Assessor at the University of Nebraska-Lincoln and a frequent contributor.)

(Article courtesy of Tree Services Magazine-

Arborist Ropes: Care and Maintenance

Care and Maintenance

 By Kate Leifheit

(Pick a color, any color.  Rope manufacturers often use bright colors so arborists can quickly and easily distinguish the ropes used for various arboricultural operations. Ropes are manufactured using a multitude of construction methods and materials, resulting in different tensile strengths and stretch.  It cannot be overstated how important it is for arborists to research and learn which rope is most compatible with their climbing or rigging system.  Proper rope selection and care is vital for performing safe and effective tree care. 
Photo courtesy of ISA.)

Ropes may be considered an arborist’s most important tools. They can be used to support limbs, tools or a person. Their adequacy as a tool is based on material, construction, tensile strength, elasticity and working-load limit. Manufacturing techniques, including the way rope strands and yarns are twisted and braided, also affect the characteristics and durability of various types of rope. Because of its role in supporting tree climbers or heavy limbs in rigging operations, it is of utmost importance to purchase ropes that are approved for tree work. Arborists shall maintain their ropes in proper working order and retire them once they show signs of excessive wear.

Common factors that weaken rope

Shock loading – This is a dynamic, sudden force placed on a rope or rigging apparatus when a moving load or piece is stopped. Shock loading can occur during rigging operations when a piece of wood falls and is then caught suddenly by a rigging system. The farther a piece falls before being caught by the system the greater the amount of force generated and experienced by the rope, rigging point and rigging system. Letting a piece run and bringing it to a stop more slowly will put less force on the rigging system and rope.

Sharp edges – Sharp edges can cut or cause heavy abrasion to a rope. These edges may appear naturally on a tree and affect a rope when you are using a natural branch union. Be aware of any sharp metal pieces embedded in trees that might cut a rope under tension. Sharp edges may also be present on climbing hardware or other equipment, meaning that proper inspection before each use is critical.

Stretch – Any time a load is placed on a rope stretch can occur. The rope may bend or get caught when a portion bears the majority of the load unevenly. This is due to forces resulting from the load not being able to flow or travel well beyond a bend in the rope. Depending on the bend, the part of the rope from the bend to the load may bear almost all of the force, and the part of the rope from the bend and away from the load may bear almost none of the force. This is considered an unequal load.

Friction – Friction occurs when a rope rubs against itself, another rope, hardware or a part of the tree. The rubbing causes wear on the rope, which decreases its strength over time. Using devices like blocks, pulleys, and ring friction savers correctly can help protect a rope from wear and extend its service life. Ropes that have a mantle sheath with larger strands generally have a higher resistance to abrasion.

(ANSI Z133 Safety Requirements for Arboriculture Operations section 8.1.4 states: “Arborists shall inspect climbing lines, worklines, lanyards and other climbing equipment for damage, cuts, abrasion and/or deterioration before each use and shall remove them from service if signs of excessive wear or damage are found.” 
Photo courtesy of ISA.)

Heat – Excessive heat is a natural enemy of most materials, and rope is no exception. Arborist ropes are subjected to a lot of heat. Friction causes heat when rope rubs against blocks, equipment, rigging points, tree limbs and other objects. Rope rubbing against rope also causes hot spots. Heat is a factor in reducing a rope’s service life. It’s important to take measures to avoid excessive friction or conditions that may produce excessive heat on your rope.

Moisture – This can cause strength loss in ropes depending on the material they’re constructed from. While nylon has some absorption properties and can lose strength when wet, a material like polyester does not experience strength loss due to moisture. This is one reason why most arborist ropes are constructed from polyester. It’s recommended that you store all of your ropes in a rope bag to keep them clean and dry. Do not use excessive heat to dry your ropes, and do not store them on the ground.

Knots – Each time a knot is tied in a rope it loses a percentage of its original strength.

Signs of a weak rope

Regular rope inspection shall be performed before each use to determine if the rope is still in proper working condition. During inspection, look for the following characteristics of a weak rope:

Discoloration – This may be an indication of chemical damage.

Variance in diameter – Variance in diameter may indicate core damage.

Hard spots and contamination – These usually signify a rope is excessively worn or weakened by overloading and shock loading.

Gloss, glaze and streaks – These indicate signs of heat or friction damage.

Frays, pulls and broken strands – If more than half of the outer sheath is frayed, then you should retire the rope immediately. Broken strands may indicate the rope was torn by friction, cut by a sharp edge, or the working-load limit was exceeded. Retire the rope immediately if two or more strands are broken.

Heavy abrasion – Usually caused by friction and extreme wear.

Milking – This is the shifting of the sheath leaving a rope end without a core.

Rope care

  • Here are some simple things you can do to increase the service life of a rope and limit damage:
  • Hang your rope off the ground or keep it in a rope bag. A rope can absorb chemicals from concrete or other porous surfaces when kept on the ground.
  • Use a rope washer or wash your rope in a washing machine on a delicate cycle to clean off dirt and grit. Do not use detergents or fabric softeners, and do not put the rope in a dryer. Ropes should be hung to dry.
  • Try to use the rope on smooth, natural branch union points or use a friction-reducing device to help maintain the rope’s original strength and lessen abrasion.
  • Keep the rope away from temperatures that can cause rope damage.
  • Cut off damaged portions of the rope and rotate the use of climbing line ends if not using a spliced eye.

(Tree care operations can be hard on ropes. Dynamic loads can cause shock loading, heavy loads can exceed the rope’s working-load limit, and natural branch union rigging can cause excessive friction. For these reasons, selecting a rope that is designed for the type of work that will be performed and inspecting ropes before each use is vital. 
Photo courtesy of Baltimore City Parks;

Monitor rope use

Monitoring the use of a rope will help you assess its condition and strength during daily inspections. Avoid using a rope that has been loaded above the working-load limit. Remember that the tensile strength decreases after each use of the rope. After purchasing a rope, write down:

  • the date the rope is put into service;
  • rope tensile strength;
  • the working-load limit;
  • its type of use; and
  • the approximate latest date the rope should be retired.

Once a rope is ready to be retired from climbing or rigging applications, it can still be used as a tag line. When disposing of an old rope, it’s best to cut the rope into short lengths to prevent someone else from using it.

(Don’t store your rope near sharp objects, and make sure blades in the work zone are covered/ sheathed when not in use
Photo courtesy of ISA.)

Remember these key points about rope safety:

  • Always visually and manually inspect ropes before each use and remove from service ropes that show signs of excessive wear or damage.
  • Always keep loads under the working-load limit.
  • All climbing gear, including lanyards, hardware, saddles and splices, must be in good working condition and not be altered in a way that would compromise the integrity of the equipment.
  • Rope should be clearly marked for specific use (i.e., which ropes are for climbing and which ropes are for rigging).
  • Never leave a rope unattended in a tree.
  • Review rope regulations and standards governing your region (in the U.S., refer to ANSI Z 133-2012 Safety Requirements for Arboricultural Operations section 8.1).

Carefully monitoring rope use, selecting the right ropes for the specific purpose, adhering to safety standards, and properly maintaining and storing your ropes and other equipment will help ensure a safe and efficient worksite.

To learn more about rope construction, maintenance and selection – and earn CEUs – visit ISA’s Online Learning Center ( to take the new course, Arborist Ropes. Kate Leifheit is ISA’s former educational products coordinator.

(Article courtesy of Tree Services Magazine-