Frequently Asked Questions
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Frequently Asked Questions

ISA strives to foster a greater public awareness of the benefits of trees by assisting homeowners in obtaining the knowledge needed to help sustain trees in an urban environment. Below you will find a list of some common questions. Here, and throughout this site, homeowners will find answers and valuable resources to assist with tree care needs.

About ISA

What is the International Society of Arboriculture (ISA)?
What is the difference between an arborist and a certified arborist?
Why should I hire an arborist?
How do I find a certified arborist near by me?
How do I contact the International Society of Arboriculture?

About Trees

Why are trees beneficial?
How do I find information about tree care?
What type of tree should I buy?
How should I plant my tree?
How often does my tree need care?
What is pruning a tree?
What is topping a tree?
What is mulching?
What should I do if I think my tree has insect and/or disease problems?
Can trees be hazardous?
What should I do if my tree gets struck by lightning?

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:

© 2007 International Society of Arboriculture.


National Register of Big Trees
Big trees are symbols of all the good work trees do for the quality of the environment-and our quality of life. MORE >>

NADF Hardiness Zone Map
Find out the right tree to plant where you live MORE >>

Don't Move Firewood!

Camping Season is fast approaching. Please remember to not transport firewood. Tree-killing insects and diseases can lurk in firewood. These insects and diseases can't move far on their own, but when people move firewood they can jump hundreds of miles. New infestations destroy our forests, property values, and cost huge sums of money to control. MORE >>

National Tree Benefits Calculator
Make a simple estimation of the benefits individual street-side trees provide. With inputs of location, species and tree size, users will get an understanding of the environmental and economic value trees provide on an annual basis. For more detailed information on urban and community forest assessments, visit the i-Tree website. MORE >>

What is an Arborist and How Can You Find One?
From Planet Green a Discovery Company MORE >>


The Talking Tree

Available through the ISA Web store

What if your tree could talk?
What would it say about how to take care of it? Do you know the difference between a tree living in the city and a tree living in the forest. This book is a great tool to teach children about trees. Only $9.95.

© International Society of Arboriculture 2009
P.O. Box 3129, Champaign, IL 61826
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