| 2019 |
Stachys 'Hummelo' |
| 2018 |
ALLIUM 'Millenium' |
| 2017 |
ASCLEPIAS tuberosa |
| 2016 |
ANEMONE x 'Honorine Jobert' |
| 2015 |
GERANIUM x cantabrigiense 'Biokovo' |
| 2014 |
PANICUM virgatum 'Northwind' |
| 2013 |
POLYGONATUM 'Variegatum' |
| 2012 |
BRUNNERA macrophylla 'Jack Frost' PP13859 |
| 2011 |
AMSONIA hubrichtii |
| 2010 |
BAPTISIA australis |
| 2009 |
HAKONECHLOA macra 'Aureola' |
| 2008 |
GERANIUM x 'Rozanne' |
| 2007 |
NEPTEA x faassenii 'Walker’s Low' |
| 2006 |
DIANTHUS gratianopolitanus 'Firewitch' |
| 2005 |
HELLEBORUS x hybridus |
