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 which 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

services that an arborist provides
Arborists can provide a variety of services to help maintain your valuable investment.

1. Pruning-The arborist can determine what type of pruning is necessary to maintain or improve the health appearance and safety of your 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 pavements.
Removing diseased or insect-infested limbs.
Creating better structure to lessen wind resistance and reduce the potential for storm damage.
Training young trees.
Thinning or removal of unnecessary branches.
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.
The tree is considered irreparably hazardous.
The tree is causing an obstruction that is impossible to correct through pruning.
The tree is crowding and causing harm to other trees.
The tree is to be replaced by a more suitable specimen.
The tree should be removed to allow for new construction.

3. Emergency Tree Care

Storms may cause limbs or entire trees to fail, 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 prune. 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:

Practising 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.
Fertilisation.
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 which include:
Membership in professional organisations such as the International Society of Arboriculture (ISA),
Check in the yellow pages for those arborists who display the official logo of the ISA
Ask for proof of insurance. A reputable arborist will have public liability and professional indemnity insurance.

Many homeowners have had to pay out large amounts of money for damages caused by an uninsured individual claiming to be a tree expert. You could be held responsible for damages and injuries that occur as a result of the job. 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 work sites 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. This will take more time, but it will be worth the investment. Be wary of individuals who go door-to-door offering 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 never corrects itself. 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 which 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 who 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?

be an informed consumer

When selecting an Arborist for this list you should ensure that he / she maintains the appropriate level of insurance cover. Contractors should maintain Public & Products Liability cover to a minimum of £5,000,000 in any one event and Employers Liability Insurance with unlimited cover. If you do not get proof of these insurances do not hire the Arborist Consultants and those offering professional advice should maintain Professional Indemnity Insurance to a minimum of £500,000 in any one occurrence.
Developed by the International Society of Arboriculture (ISA), a non-profit organisation supporting tree care research around the world and 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.