Gardeners Club
- A directory of all local and national gardening related clubs, societies and organisations in the UK.
- http://www.gardenersclub.co.uk/societiesinfo.asp

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/

City Farmer's Urban Agriculture Notes
- A non-profit society that promotes urban food production and environmental conservation.
- http://www.cityfarmer.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/

International Code of Nomenclature for Cultivated Plants
- An extensive list of worldwide contacts of associations organised in taxonomic order.
- http://www.ishs.org/sci/icralist/icralist.htm

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.rbg.ca/cbcn/

The Brown Lawn Society
- Organization encouraging environmentally friendly methods for lawn care such as the reuse of rainwater and natural pest collectors.
- http://www.brownlawnsociety.org

Lesbian Gardens
- Special thoughts on growing plants, various links and member information.
- http://lesbiangardens.net/