Public education is very important, but as far as landscape practices and related matters, it currently only reaches the small percentage of folks who manage their own landscapes as well as professionals who are predisposed to favor the environment.
Keep pushing with public education, though. Connect homeowners as "employers" with responsibility for what work they hire done, and its impact on the environment. Teaching kids about environmentally-friendly landscape practices, those that aren't, and how to tell the difference will make them better informed future consumers.
"Out of the box" thinking will be needed to engage the majority of landscape professionals. Engaging them in large numbers could have dramatic results, but like anyone, they'll be largely motivated by "what is in it for me?"
There is a interdependent network of businesses and people whose success and livelihood depends on business as usual. That is, chemically dependent, gas guzzling, lawn-based monocultures that hurt the environment but are the hallmark of status within our urban/suburban culture. Finding ways to build consensus with these people will be key. And, incremental change can be better than no change at all.
CLCA [California Landscape Contractors' Association], and their CEUs and seminars at industry shows might be a starting point.