Why Hire an Arborist?
An arborist is a specialist in the care of individual trees. Arborists are knowledgeable about the needs of trees and are trained and equipped to provide proper care. Hiring an arborist is a decision that should not be taken lightly. Proper tree care is an investment that can lead to substantial returns. Well cared-for trees are attractive and can add considerable value to your property. Poorly maintained trees can be a significant liability. Pruning or removing trees, especially large trees, can be dangerous work. Tree work should only be done by those trained and equipped to work safely in trees. ISA Certified Arborist List Services That Arborists Can Provide

1. Pruning - The arborist can determine what type of pruning is necessary to maintain or improve the health, appearance, and safety of trees. These techniques include:

• Eliminating branches that rub each other.
• Removing limbs that interfere with wires, building facades, gutters, roofs, chimneys, windows, or that obstruct streets or sidewalks.
• Removing dead or weak limbs that pose a hazard or may lead to decay.
• Removing diseased or insect-infested limbs.
  
• Creating better structure to lessen wind resistance and reduce the potential for storm damage.
  
• Training young trees.
  
• Removing limbs damaged by adverse weather conditions.
  
• Thinning or removal of branches to increase light penetration.
  
• Improving the shape or silhouette of the tree.

2. Removal - Although tree removal is a last resort, there are circumstances when it is necessary. An arborist can help decide whether or not a tree should be removed. Arborists have the skills and equipment to safely and efficiently remove trees. Removal is recommended when the tree:

• Is dead or dying.
• Is considered irreparably hazardous.
• Is causing an obstruction that is impossible to correct through pruning.
• Is crowding and causing harm to other trees.
• Is to be replaced by a more suitable specimen.
• Should be removed to allow for new construction.

3. Emergency Tree Care - Storms may cause limbs or entire trees to fall, often landing on homes, cars, other structures, or other trees. The weight of storm-damaged trees is great, and they can be very dangerous to remove or trim. An arborist can assist in performing the job in a safe manner, while reducing further risk of damage to your property.

4. Planting - Some arborists plant trees and most can recommend what types of trees are appropriate for a specific location. The wrong tree in the wrong location could lead to future problems due to limited growing space, insects, diseases, or poor growth.

5. Other Services - Many arborists also provide a variety of other tree care services including:

• Practicing Plant Health Care; a concept of preventive maintenance to keep trees in good health, which will help the tree better defend itself against insects, disease, and site problems.
• Fertilization.
• Cabling or bracing for added support to branches with weak attachment.
• Aeration to improve root growth.
  
• Installation of lightning protection systems.
  
• Spraying or injecting to control certain insect and disease problems. Selecting the Right Arborist for the Job There are a variety of things to consider when selecting an arborist including:
  
  
  • Membership in professional organizations- such as the International Society of Arboriculture (ISA), the Tree Care Industry Association, or the American Society of Consulting Arborists (ASCA)-demonstrates a willingness on the part of the arborist to stay up-to date on the latest techniques and information.
    
    
  • Check in the phone directory yellow pages for those arborists who advertise as ISA Certified Arborists or display the official logo of the ISA Certified Arborist. Certified arborists are experienced professionals who have passed an extensive examination covering all aspects of tree care.
    
    
  • Ask for proof of insurance and then phone the insurance company if you are not satisfied. A reputable arborist will have personal and property damage insurance as well as worker's compensation insurance. Many homeowners have had to pay out large amounts of money for damages caused by uninsured individuals claiming to be a tree experts. You could be held responsible for damages and injuries that occur as a result of the job.
    
    
  • Some governmental agencies require contractors to apply for permits and/or to apply for a license before they are able to work. Be sure they comply with any local, state, provincial, or national law that governs their work.
    
    
  • Ask for references to find out where the company has done work similar to the work you are requesting. Don't hesitate to check references or visit other worksites where the company or individual has done tree work. Remember, tree care is a substantial, long-lasting investment; you would not buy a car without a test drive!
    
    
  • Unless you know and are comfortable with the arborist, get more than one estimate. You may have to pay for the estimates, and it will take more time, but it will be worth the investment.
    
    
  • Be wary of individuals who go door-to-door and offer bargains for performing tree work. Most reputable companies are too occupied to solicit work in this manner. Improper tree care can take many years to correct itself, and in some cases, it can never be corrected. Are you willing to take that risk with your valuable investment?
    
    
  • Good arborists will only perform accepted practices. For example, practices such as topping a tree, removing an excessive amount of live wood, using climbing spikes on trees that are not being removed, and removing or disfiguring living trees without just cause are unnecessary.
    
    
  • Don't always accept the low bid. You should examine the credentials and the written specification of the firms that submitted bids and determine the best combination of price, work to be done, skill, and professionalism to protect your substantial investment.
    
    
  • Get it in writing. Most reputable arborists will have their clients sign a contract. Be sure to read the contract carefully. Don't be afraid to ask questions, such as: - When will the work be started and completed? - Who will be responsible for clean-up? - Is this the total price? - If I would like more to be done, what is your hourly rate?
    
    
  • What Is a Certified Arborist? An arborist by definition is an individual who is trained in the art and science of planting, caring for, and maintaining individual trees. ISA Arborist Certification is a non-governmental, voluntary process by which individuals can document their base of knowledge. It operates without mandate of law and is an internal, self-regulating device administered by the International Society of Arboriculture. Certification provides a measurable assessment of an individual's knowledge and competence required to provide proper tree care. Certification is not a measure of standards of practice. Certification can attest to the tree knowledge of an individual but cannot guarantee or ensure quality performance. Certified arborists are individuals who have achieved a level of knowledge in the art and science of tree care through experience passing a comprehensive examination developed by some of the nation's leading experts on tree care. Certified arborists must also continue their education to maintain their certification. Therefore, they should be up-to-date on the latest techniques in arboriculture.

Developed by the International Society of Arboriculture (ISA), a non-profit organization supporting tree care research around the world and is dedicated to the care and preservation of shade and ornamental trees. For further information, contact: ISA, P.O. Box 3129, Champaign, IL 61826-3129, USA. E-mail inquires: isa@isa-arbor.com © 1995 International Society of Arboriculture. UPDATED JULY 2003
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Benefits of Trees
Most trees and shrubs in cities or communities are planted to provide beauty or shade. These are two excellent reasons for their use. Woody plants also serve many other purposes, and it often is helpful to consider these other functions when selecting a tree or shrub for the landscape. The benefits of trees can be grouped into social, communal, environmental, and economic categories. Social Benefits We like trees around us because they make life more pleasant.

Most of us respond to the presence of trees beyond simply observing their beauty. We feel serene, peaceful, restful, and tranquil in a grove of trees. We are "at home" there. Hospital patients have been shown to recover from surgery more quickly when their hospital room offered a view of trees. The strong ties of people and trees are most evident in the resistance of community residents to removing trees to widen streets. Or we note the heroic efforts of individuals and organizations to save particularly large or historic trees in a community. The stature, strength, and endurance of trees give them a cathedral-like quality. Because of the potential for long life, trees are frequently planted as living memorials. We often become personally attached to trees that we or those we love have planted.

Communal Benefits
Even though trees may be private property, their size often makes them part of the community as well. Since trees occupy considerable space, planning is required if both you and your neighbors are to benefit. With proper selection and maintenance, trees can enhance and function on one property without infringing upon the rights and privileges of neighbors. City trees often serve several architectural and engineering functions. They provide privacy, emphasize views, or screen out objectionable views. They reduce glare and reflection. They direct pedestrian traffic. They provide background, soften, complement, or enhance architecture. Trees bring natural elements and wildlife habitats into urban surroundings, all of which increase the quality of life for residents of the community.

Environmental Benefits
Trees alter the environment in which we live by mode rating climate, improving air quality, conserving water, and harboring wildlife. Climate control is obtained by moderating the effects of sun, wind, and rain. Radiant energy from the sun is absorbed or deflected by leaves on deciduous trees in the summer and is only filtered by branches of deciduous trees in winter. We are cooler when we stand in the shade of trees and are not exposed to direct sunlight. In winter, we value the sun's radiant energy; and because of this, we should plant only small or deciduous trees on the south side of homes. Wind speed and direction can be affected by trees. The more compact the foliage on the tree or group of trees, the greater the influence of the windbreak. The downward fall of rain, sleet, and hail is initially absorbed or deflected by trees and this provides some protection for people, pets, and buildings. Trees int ercept water, store some of it, reduce storm run-off, and the possibility of flooding. Dew and frost are less common under trees because less radiant energy is released from the soil in those areas at night.

Temperature in the vicinity of trees is cooler than that away from trees. The larger the tree, the greater the cooling. By using trees in the cities, we are able to moderate the heat island effect caused by pavement and buildings in commercial areas. Air quality can be improved through the use of trees, shrubs, and turf. Leaves filter the air we breathe by removing dust and other particulates. Rain washes the pollutants to the ground. Leaves absorb carbon dioxide from the air to form carbohydrates that are used in the plant's structure and function. In this process, leaves also absorb other air pollutants - such as ozone, carbon monoxide, and sulfur dioxide and give off oxygen. By planting trees and shrubs, we return to a more natural, and less artificial environment. Birds and other wildlife are attracted to the area. The natural cycles of plant growth, reproduction, and decomposition are again present, both above and below ground. Natural harmony is restored to the urban environment.

Economic Benefits
Property values of landscaped homes are 5-20% higher than those of non-landscaped homes.Ê Individual trees and shrubs have value, but the variability of species, size, condition, and function makes determining their economic value quite difficult. The economic benefits of trees can be both direct and indirect.Ê Direct economic benefits are usually associated with energy costs. Air conditioning costs are lower in a tree-shaded home. Heating costs are reduced when a home has a windbreak. Trees increase in value from the time they are planted until they mature. Trees are a wise investment of funds since landscaped homes are more valuable than non-landscaped homes. The savings in energy costs and the increase in property value directly benefit each homeowner.

The indirect economic benefits of trees are even greater. These are available to the community or region. Lowered electricity bills are paid by customers when power companies are able to use less water in their cooling towers, build fewer new facilities to meet peak demands, use reduced amounts of fossil fuel in their furnaces, and need fewer measures to control air pollution. Communities can also save if fewer facilities must be built to control storm water in the region. To the individual these savings are small, but to the community, reductions in these expenses are often in the thousands of dollars. Trees Require an Investment Trees provide numerous aesthetic and economic benefits but also incur some costs. You need to be aware that an investment is required for your trees to provide the benefits that you desire. The biggest cost of trees and shrubs occurs when they are purchased and planted. Initial care almost always includes some watering. Leaf, branch, and whole tree removal and disposal can be expensive.

To function well in the landscape, trees require maintenance. Much can be done by the informed homeowner. Corrective pruning and mulching will give trees a good start. Shade trees, however, quickly grow to a size that may require the services of a professional arborist. Arborists have the knowledge and equipment needed to prune, spray, fertilize, and otherwise maintain a large tree. Your garden center owner, cooperative extension agent, community forester, or consulting arborist can answer questions about tree maintenance, suggest treatments, or recommend qualified arborists. The PHC Alternative Maintaining mature landscapes is a complicated undertaking. You may wish to consider a professional Plant Health Care (PHC) maintenance program which is now available from many landscape care companies. Their program is designed to maintain plant vigor and should initially include inspections to detect and treat any existing problems which could be damaging or fatal. Thereafter, regular inspections and preventive maintenance will ensure plant health and beauty. Refer to our Plant Health Care brochure for more information.

Developed by the International Society of Arboriculture (ISA), a non-profit organization supporting tree care research around the world and is dedicated to the care and preservation of shade and ornamental trees. For further information, contact: ISA, P.O. Box 3129, Champaign, IL 61826-3129, USA. E-mail inquires: isa@isa-arbor.com © 1995 International Society of Arboriculture. UPDATED JULY 2003. Back to top

Why Topping Hurts Trees Topping is perhaps the most harmful tree pruning practice known. Yet, despite more than 25 years of literature and seminars explaining its harmful effects, topping remains a common practice. This brochure explains why topping is not an acceptable pruning technique and offers better alternatives. What is Topping? Topping is the indiscriminate cutting of tree branches to stubs or lateral branches that are not large enough to assume the terminal role. Other names for topping include "heading," "tipping," "hat-racking," and "rounding over." The most common reason given for topping is to reduce the size of a tree. Often homeowners feel that their trees have become too large for their property. People fear that tall trees may pose a hazard. Topping, however, is not a viable method of height reduction and certainly does not reduce the hazard. In fact, topping will make a tree more hazardous in the long term

Topping Stresses Trees Topping often removes 50-100% of the leaf-bearing crown of a tree. Since the leaves are the food factories of a tree, this can temporarily starve a tree. The severity of the pruning triggers a sort of survival mechanism. The tree activates latent buds forcing the rapid growth of multiple shoots below each cut. The tree needs to put out a new crop of leaves as soon as possible. If a tree does not have the stored energy reserves to do this, it will be seriously weakened and may die. A stressed tree is more vulnerable to insect and disease infestations. Large, open pruning wounds expose the sapwood and heartwood to attacks. The tree may lack sufficient energy to chemically defend the wounds against invasion, and some insects are actually to the chemical signals trees release.

Topping Creates Hazards. The survival mechanism that causes a tree to produce multiple shoots below each topping cut comes at great expense to the tree. These shoots develop from buds near the surface of the old branches. Unlike normal branches that develop in a socket of overlapping wood tissues, these new shoots are anchored only in the outermost layers of the parent branches. The new shoots grow very quickly, as much as 20 feet in one year, in some species. Unfortunately, the shoots are very prone to breaking, especially during windy conditions. The irony is that while the goal was to reduce the tree's height to make it safer, it has been made more hazardous than before.

Topping Makes Trees Ugly The natural branching structure of a tree is a biological wonder. Trees form a variety of shapes and growth habits, all with the same goal of presenting their leaves to the sun. Topping removes the ends of the branches, often leaving ugly stubs. Topping destroys the natural form of a tree.Ê Without the leaves (up to 6 months of the year in temperate climates) a topped tree appears disfigured and mutilated. With the leaves, it is a dense ball of foliage, lacking its simple grace. A tree that has been topped can never fully regain its natural form. Topping is Expensive The cost of topping a tree is not limited to what the perpetrator is paid. If the tree survives, it will require pruning again within a few years. It will either need to be reduced again or storm damage will have to be cleaned up. If the tree dies, it will have to be removed. Topping is a high maintenance pruning practice, and there are some hidden costs of topping. One is the reduction in property value. Healthy, well maintained trees can add 10-20% to the value of a property. Disfigured, topped trees are considered an impending expense. Another potential cost of topped trees is the potential liability. Topped trees are prone to breaking and can be hazardous. Since topping is considered to be an unacceptable pruning practice, any damage caused by branch failure of a topped tree may lead to a finding of negligence in a court of law.

Alternatives to Topping There are times when a tree must be reduced in height or spread. Providing clearance for utility lines is an example. There are recommended techniques for doing this. If practical, branches should be removed back to their point of origin. If a branch must be shortened, it should be cut back to a lateral that is large enough to assume the terminal role. A rule of thumb for this is to cut back to a lateral that is at least 1/3 the diameter of the limb being removed. This method of branch reduction helps to preserve the natural form of the tree. However, if large cuts are involved, the tree may not be able to close over and compartmentalize the wounds. Sometimes the best solution is to remove the tree and replace it with a species that is more appropriate for the site.

Hiring an Arborist
Pruning large trees can be dangerous. If pruning involves working above the ground or using power equipment, it is best to hire a professional arborist. An arborist can determine what type of pruning is necessary to improve the health, appearance, and safety of your trees. A professional arborist can provide the services of a trained crew, with all of the required safety equipment and liability insurance.

There are a variety of things to consider when selecting an arborist:

• Membership in professional organizations such as the International Society of Arboriculture (ISA), the Tree Care Industry Association (TCIA), or the American Society of Consulting Arborists (ASCA).
• Certification through the ISA Certified Arborist program.
• Proof of insurance.
• A list of references (Don't hesitate to check.)
• Avoid using the services of any tree company that: - Advertises topping as a service provided. Knowledgeable arborists know that topping is harmful to trees and is not an accepted practice. - Uses tree climbing spikes to climb trees that are being pruned. Climbing spikes can damage trees, and their use should be limited to trees that are being removed.

Developed by the International Society of Arboriculture (ISA), a non-profit organization supporting tree care research around the world and is dedicated to the care and preservation of shade and ornamental trees. For further information, contact: ISA, P.O. Box 3129, Champaign, IL 61826-3129, USA. E-mail inquires: isa@isa-arbor.com © 1995 International Society of Arboriculture. UPDATED JULY 2003. Back to top