American Public Gardens Association
- Supporting the public horticulture community in its mission to study, display, and conserve plants.
- http://www.publicgardens.org/

The Gesneriad Society
- Offers culture information, membership benefits, resources, photos and flower show and sales schedules.
- http://www.gesneriadsociety.org/

The Ecological Landscaping Association
- Advocates environmentally responsible landscaping and horticultural practices by professionals and the public. Information about events, newsletter, and membership.
- http://www.ecolandscaping.org/

The New England Botanical Club
- Promotes the study of the plants of North America, especially the flora of New England and adjacent areas.
- http://www.rhodora.org/

American Bamboo Society
- Offers information about bamboo including a species source list, a list of international bamboo societies, information on climate anc growing zones.
- http://www.americanbamboo.org/

The Gardeners of America/Men's Garden Clubs of America (TGOA/MGCA)
- Organization with local chapters around the USA, focusing on gardening education and community gardening initiatives. Information about membership, clubs, and events.
- http://tgoa-mgca.org/

Pioneer Valley Water Garden and Koi Club
- Club for Western Massachusetts and Northern Connecticut provides listing of club officers, meeting schedule, pond tour photos, and a membership application.
- http://www.pioneervalleypondclub.com/

Deep South Region of National Garden Clubs, Inc.
- Information about Federated Garden Clubs and their projects in the states of Alabama, Florida, Georgia, Louisiana, Mississippi and Tennessee.
- http://www.dsregion.org/

National Garden Clubs
- Provides education, resources and national networking opportunities for its members to promote gardening and floral design. Includes calendar of events, educational opportunities and image galleries.
- http://www.gardenclub.org/

National Capital Area Federation of Garden Clubs, Inc.
- Washington-area chapter of the National Garden Clubs, representing over a hundred area clubs. Provides membership information, news, event calendar, and links to local gardening groups and affiliates.
- http://gardencentral.org/ncafgc

Hardy Plant Society Mid Atlantic Group
- Gardening society centered around the Philadelphia area. Brief information and membership signup form.
- http://www.hardyplant.org/

American Horticultural Society
- The AHS mission is to educate and inspire people to become successful and environmentally responsible gardeners by advancing the art and science of horticulture.
- http://www.ahs.org/

Northern Gardener
- Home to Northern Gardener Magazine and the Minnesota State Horticultural Society. Features gardening articles, advice, tips, calendar, and resources.
- http://www.northerngardener.org/

National Home Gardening Club
- Member-oriented site for this United States gardeners' club, providing access to bulletin boards, members' photos, articles from the magazine, and member benefits.
- http://www.gardeningclub.com/

Oasis Botanical Sanctuary
- Uses scientific research to educate the public on the proper methods of ecological development.
- http://oasisproject.us/

National Gardening Association
- A non-profit organization offering National Gardening Magazine, educational and youth programs, gardening products, books, research, online content and showcases, and a gardeners buying guide.
- http://www.garden.org/

American Society of Landscape Architects
- Founded in 1899, the society has twelve thousand members. Includes a buyers guide on landscape information.
- http://www.asla.org/

American Conifer Society
- Information on the more than five hundred species of conifers distributed around the world.
- http://www.conifersociety.org/

Mid South Hosta Society
- Gardening club devoted to hostas.
- http://www.mshosta.com/

Heartland Peony Society
- Educational information on peonies and specific information on the society in the US midwest.
- http://www.peonies.org/

Cycad Society
- Education and conservation of Cycads, rare and unusual gymnosperm plants. Quarterly newsletter and a seed bank available to members.
- http://www.cycad.org/

African Violet Society of America
- Presenting information about growing, showing and propagating African violets and other gesnariads.
- http://www.avsa.org/

Gardening Organizations and Associations
- Information on events, newsletter, tips, children's projects, and gardening information.
- http://www.gardenclub.net/orgs.htm

Holly Society of America
- Provides an information exchange through scientific studies, publications, lectures, meetings, and visiting holly collections.
- http://www.hollysocam.org/