At the turn of the 20th Century, there was no Better Business Bureau, Federal Trade Commission, or any kind of state licensing laws regulating the sale of horticultural products, and as a result, consumers were the targets of many unscrupulous merchandisers making fabulous claims for ordinary plants and often selling misrepresented seeds and plants at cheap prices. Throughout the country, nursery owners and professional horticulturists recognized the damage these practices could do for the reputation of the legitimate trade, and they began banding together in professional organizations to help promote sound, honest horticultural products and practices.

The direct impetus that brought the St. Louis group together, to ultimately form the Landscape and Nurserymen's Association of Greater St. Louis, was the passing by Congress the National Industrial Recovery Act of 1933, an effort to combat unemployment from the Great Depression. One condition of that act was the advent of the 40-hour work week, and local nursery owners were concerned how that would affect their businesses. But over the years, they also dealt with the same fair trade issues that spawned other organizations, and public and professional education became a central focus of the LNAGSL's charter.