2020
Amsonia



2019
Baptisia


2018
Astrantia


2017
Geranium


2016
Veronicastrum


2015
Phlox


2014
Salvia


2013
Aster


2012
Nepeta


2011
Campanula


2010
Helenium


2009
Echinacea


2008
Leucanthemum


2007
Veronica
2020
Amsonia
2019
Baptisia
2018
Astrantia
2017
Geranium
2016
Veronicastrum
2015
Phlox
2014
Salvia
2013
Aster
2012
Nepeta
2011
Campanula
2010
Helenium
2009
Echinacea
2008
Leucanthemum
2007
Veronica