American Clematis Society
http://clematis.org
The American Clematis Society (ACS) is a society of Clematis enthusiasts. It was founded in order to share in the enjoyment of Clematis as well as to promote them. ACS is a non-profit plant society founded in 1996 for the purpose of encouraging and promoting the development and improvement of Clematis and to collect, record and share information concerning Clematis.

American Hemerocallis Society (AHS)
http://www.daylilies.org
The American Hemerocallis Society, Inc. (AHS) is a non-profit organization. The AHS is organized exclusively for educational and scientific purposes, and especially to promote, encourage, and foster the development and improvement of the genus Hemerocallis and public interest therein.

American Hosta Society
http://www.hosta.org
Welcome to the American Hosta Society (AHS) and the wonderful world of Hosta.

The American Hosta Society is a society of people, whose focus is centered on the "friendship plant". We are organized for educational and scientific purposes, and especially to promote, encourage, and foster the development, improvement, and enjoyment of the genus Hosta.

American Iris Society (AIS)
http://www.irises.org
Welcome to the American Iris Society (AIS) website. We hope that you will find this website an informative and helpful resource to all kinds of iris information.

American Peony Society
http://www.americanpeonysociety.org
Welcome to the American Peony Society home page. We believe the best way to generate interest in the plant is by sharing information. The website is intended to be informative and educational on a wide range of peony topics, everything from backyard planting to the use of peonies as a study-plant. If you are not familiar with peonies, or with hybrid notation, the Introductory Information section is suggested reading.

British Clematis Society
http://www.britishclematis.org.uk
Welcome to the British Clematis Society website. This site will provide the gardener with planting, pruning and general growing information on Clematis.

International Clematis Society
http://dialspace.dial.pipex.com/clematis
This site will provide the gardener with planting, pruning and general growing information on Clematis.

Mailorder Gardening Association
http://www.mailordergardening.com
The Mailorder Gardening Association is a member organization of mailorder gardening and garden magazine companies. The ultimate goal of the MGA is to provide the finest gardening products, information, and service through the catalogs and magazines of its members.

National Gardening Association (NGA)
http://www.garden.org/home
The National Gardening Association (NGA), founded in 1973, is a nonprofit leader in plant-based education. We serve a national audience with timely materials designed to foster an appreciation for the benefits of gardening.

Plants have the power to change our lives. They enable the simple and therapeutic pleasure of working in one's own garden. They play a basic role in providing clean air and serve as a nutritious basis for healthy living. And they are uniquely effective teaching tools. For more than 30 years, NGA has been working to renew and sustain the essential connection between people, plants, and the environment through gardening.

Our programs and initiatives highlight the opportunities for plant-based education in schools, communities, and backyards across the country. We serve as a bridge to connect people to gardening in five core fields: plant-based education, health and wellness, environmental stewardship, community development, and responsible home gardening.

Perennial Plant Association (PPA)
http://www.perennialplant.org
A professional trade association dedicated to improving the perennial plant industry by providing education to enhance the production, promotion and utilization of perennial plants.