APLD -    Association of Professional Landscape Designers
O.S.U. Extension Service -
Oregon State University Extension and Experiment Station. A gardening resource.
American Rhododendron Society - Portland Chapter
Portland Parks-Crystal Springs
-    Information on Crystal Springs from the Portland Parks Department
Pacific NW Sculptors
-    A regional organization of professional and amateur sculptors. Features an extensive gallery
of outdoor and indoor works.
Houzz - Portland Landscape Architects & Landscape Designers