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 be done only by those trained and equipped to work safely in trees.
An arborist can determine the type of pruning 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, or 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
- removing branches, or thinning, to increase light penetration
- improving the shape or silhouette of the tree
Removal
Although tree removal is a last resort, there are circumstances when it is necessary. An arborist can help decide whether 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
- is located in an area where new construction requires removal
Emergency Tree Care
Storms may cause limbs or entire trees to fall, often landing on other trees, homes and other structures, or cars. The weight of storm-damaged trees is great, and they can be dangerous to remove or trim. An arborist can assist in performing the job in a safe manner, while reducing further risk of damage to property.
Planting
Some arborists plant trees, and most can recommend types of trees that are appropriate for a specific location. The wrong tree in the wrong location could lead to future problems as a result of limited growing space, insects, diseases, or poor growth.
Other Services
Many arborists also provide a variety of other tree care services, including
- 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
When selecting an arborist,
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 nongovernmental, 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 and by 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 are more likely to be up to date on the latest techniques in arboriculture.
Be an Informed Consumer
One of the best methods to use in choosing an arborist is to educate yourself on some of the basic principles of tree care. ISA offers several other brochures in this series, which discuss many of the basic principles of tree care. Your local garden center, extension agent, or city arborists are also excellent sources of information if you should have further questions. They may also be able to refer you to an ISA Certified Arborist in your area.
E-mail inquiries: isa@isa-arbor.com
(c) 1998, 2004 International Society of Arboriculture.
UPDATED JULY 2005
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
© 2007 International Society of Arboriculture.