Canadian Botanical Conservation Network
A registered charitable organization which helps conserve biological diversity through networking tools and conservation programs for botanical gardens and arboreta.
http://www.bgci.org/canada/Canadian_botanical_conser/
City Farmer's Urban Agriculture Notes
A non-profit society that promotes urban food production and environmental conservation.
http://www.cityfarmer.org/
International Code of Nomenclature for Cultivated Plants
A list of worldwide contacts of associations organised in taxonomic order.
http://www.ishs.org/sci/icralist/icralist.htm
The Garden Club of America
Umbrella organization for US and Canadian local garden clubs. Sites lists clubs and their websites, botanical gardens, pamphlets, and position papers.
http://www.gcamerica.org/
The Mediterranean Garden Society
International society for gardeners in Mediterranean climates. History, membership information, journal contents, news, and event listing.
http://www.mediterraneangardensociety.org/
The Professional Gardeners Guild
An organisation for gardeners employed in private gardens and estates. Based in the UK with members in European countries and the United States.
http://www.pgg.org.uk/