We are delighted to win the award as it always helps add commercial value."
Some garden writers Steve and Val Bradley, RHS The Garden Magazine features editor, Phillip Clayton, retired nursery man Peter Higgs and Floramedia MD Nick Mathias judged the award.
Steve Bradley said: "Cassis is an unusual colour with unusual markings on the flower and also it’s the size and height of Clematis that will suit the smaller gardens we are getting these days.
This is the fourth time I have judged this award and the quality keeps getting higher. The English growers seem to be responding to the home grown trend and showing the Dutch how to grow plants well."
Cassis edged out Buddleja ‘Sugar Plum’ introduced by Lowaters Nursery’s Garden Beauty brand which the judges gave second place.
Hydrangea Paniculata ‘Wims Red’ introduced by Premier Plants came third. For more winners and plant introductions from Woking see Horticulture Week 23 July.