Illinois State Horticulture Society (ISHS)
http://www.specialtygrowers.org/horticulture.htm

Learn more about horticulture in Illinois.

            
American Society for Horticultural Science (ASHS)
http://www.ashs.org/

Learn more about horticultural research and education.

International Plant Propagators Society (IPPS)
http://www.ipps.org/

Learn more about plant production and propagation.

Society for In Vitro Biology (SIVB)
http://www.sivb.org/

Learn more about tissue culture production of horticultural crops.

  
International Association for Plant Biotechnology (IAPB)
http://www.iapb-stl.org/

Learn more about applications of plant biotechnology in horticulture.

American Horticultural Society (AHS)
http://www.ahs.org/

Learn more about professional horticulture and gardening.