About two dozen non-native plants have escaped Southern California gardens and are threatening a number of the state's plants and animals. Not only are these invasive plants very difficult to control, they are on sale in local nurseries.

The problem is visible high in the San Gabriel Mountains, above Sierra Madre, where Sturtevant Falls spills into Big Santa Anita Canyon. For more than a century, people have come to this secluded spot to escape the city.

To read the whole story, or to listen to the recording, click here: http://www.scpr.org/news/2010/11/23/21166/bad-seeds-part-2-invasive-plan...