Nonprofit organization dedicated to the restoration of the American elm tree, Ulmus americana. Includes information about Dutch elm disease and the American Liberty elm, a group of cultivars with resistance to this fungal disease.

Devoted to elm trees and elm care with sections dealing with diseases (including Dutch elm disease), new research, tree physiology and other elm-related information.

The SDEDA is an association created to preserve the American Elm in Saskatchewan. Provides information on Dutch Elm Disease and ways to battle the disease.

Dedicated to the restoration of the American Chestnut through scientific breeding and cooperative research.

Charitable organization to promote the American chestnut: organization and biological news.