2023 Pitzer College
2022 Los Angeles Pierce College - Fernando Garcia-Ibarra
Los Angeles County Arboretum and Botanical Gardens
2021 Rancho Los Alamitos - Matthew Castner
Mt. San Antonio College - Marisa Virgen
The Huntington Library, Art Museum, and Botanical Gardens - Bridget Lee
2020 Theodore Payne Foundation - Sharon Zarate
2018 California State University, Northridge
Rancho Santa Ana Botanic Garden
2017 Rancho Los Alamitos (deferred to 2021)
2016 LA County Museum of Natural History
Robinson Gardens
2015 Rancho Los Cerritos
2014 Descanso Gardens
2013 Los Angeles Arboretum
2012 The Huntington
2011 Theodore Payne Foundation
South Coast Botanic Garden
2010 Rancho Los Cerritos
Cal State University, Northridge
2009 Rancho Santa Ana Botanic Gardens
Rancho Los Alamitos
Pitzer College
2008 Robinson Gardens
2007 Descanso Gardens
Los Angeles Arboretum
2006 The Huntington
Theodore Payne Foundation
2005 South Coast Botanic Garden
Cal State University, Northridge
2004 Rancho Santa Ana Botanic Gardens
Rancho Los Alamitos
2003 Mildred Mathias Garden, UCLA
Robinson Gardens
2002 Descanso Gardens
Los Angeles Arboretum
2001 The Huntington
Theodore Payne Foundation
2000 Mildred Mathias Garden, UCLA
Los Angeles Arboretum
1998 Theodore Payne Foundation
1997 Los Angeles Arboretum
1996 Rancho Santa Ana Botanic Gardens
Descanso Gardens
1995 Descanso Gardens
1994 Robinson Gardens
Rancho Santa Ana Botanic Gardens
1993 The Huntington
Descanso Gardens
1992 Los Angeles Arboretum
The Huntington
1991 Los Angeles Arboretum