ALCA
http://www.azlca.com/azlca/
AACM
http://www.aacmonline.org/
Desert Botanical Gardens
http://www.dbg.org/
Landscape Plants AZ Desert online
http://www.amwua.org/plants_index.html
International Society of Arboriculture
http://www.isa-arbor.com/
Water Conservation Tips
http://www.wateruseitwisely.com/region/arizona/
Plant Encyclopedia
http://theplantencyclopedia.org/wiki/Main_Page