findings and principles

St. Louis Invasive Plants Species Workshop
Linking Ecology and Horticulture
to Prevent Plant Invasions

                     Findings and Principles


  • People are major dispersers of plants.  
  • The magnitude of this dispersal is unprecedented and has allowed dispersal of species that manifest aggressive traits in new areas.  
  • Plant introduction and improvement are the foundation of modern agriculture and horticulture, yielding diversity to our supply of plants used for food, forestry, landscapes and gardens, medicinal and other purposes.  
  • A small proportion of introduced plant species become invasive and cause unwanted impacts to natural systems and biological diversity as well as economies, recreation, and health.  
  • Plant species can be invasive in some regions, but not in others. 
  • The impacts of invasive plant species can occur at times and places far removed from the site of introduction.

Principles (a.k.a. The St. Louis Six)

  1. Plant introduction should be pursued in a manner that both acknowledges and minimizes unintended harm.
  2. Efforts to address invasive plant species prevention and management should be implemented consistent with national goals or standards, while considering regional differences to the fullest extent possible.
  3. Prevention and early detection are the most cost effective techniques that can be used against invasive plants.
  4. Research, public education and professional training are essential to more fully understanding the invasive plant issue and positively affecting consumer demand, proper plant use, development of non-invasive alternatives, and other solutions.
  5. Individuals from many fields must come together to undertake a broad-based and collaborative effort to address the challenge, including leaders in horticulture, retail and wholesale nurseries, weed science, ecology, conservation groups, botanical gardens, garden clubs, garden writers, educational institutions, landscape architects, foundations and government. 
  6. A successful invasive plant species strategy will make use of all available tools including voluntary codes of conduct, best management practices, and appropriate regulation.Codes of conduct for specific communities of interest are an essential first step in that they encourage voluntary initiative, foster information exchange, and minimize the expense of regulation.
This information was copied from
Please visit this site for more information on the draft codes of conduct.

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