Internet Resources

Society of American Foresters

http://www.safnet.org/

USDA Plant Site

http://plants.usda.gov/

International Society of Arboriculture

http://www.isa-arbor.com/home.aspx

Tree Care Industry Association

http://www.treecareindustry.org/index.aspx

Penn State Extension

http://www.extension.psu.edu/

Ohio State University

http://plantfacts.osu.edu/web/

Cornell University

http://plantclinic.cornell.edu/