Brown said he has been visiting the dahlia trials at Wisley for more than 60 years. He was on the original joint RHS/NDS dahlia committee and subsequent dahlia committee, which was part of the herbaceous committee.
Three years ago the RHS decided to finish the trials from the end of 2015, he said. "The trials hierarchy in the RHS decided they wanted to rotate the trials to include more variety and permanent trials would be discontinued. This came as a bombshell to most of us on the forum. We made several cases for the continuance of the dahlia trials but it would appear to have fallen on deaf ears."
"What did not make sense was in the meantime the RHS had invited the NDS to hold their annual show in conjunction with the RHS Wisley show, which meant the dahlia trials would not be there to complement the show or vice versa." He added that the RHS is the international registrar of dahlia cultivars and the dahlia trials "were of a great help with registration of new cultivars".
"The dahlia trials were a crowd-drawing display. People came from far and wide. Also, the flowering period of the dahlia meant the trials field was still full of colour long after most of the other trials finished. In fact, last year the dahlias were still in flower there in early November. The loss of the trials was like a hammer blow. I sincerely hope that it will not be too long before dahlias once again grace the trials field and our very knowledgeable dahlia forum once again being able to judge and award AGM (Award of Garden Merit) dahlias."
RHS trials development manager Mark Heath said: "The RHS trials programme aims to reflect the rapidly growing and ever-changing range of plants that are available to UK gardeners. We are keen to trial as wide a variety of plants as possible so more gardeners can try more plants with greater confidence because they know they have been through the exhaustive RHS trials process and been awarded the charity's AGM.
"Although dahlias won't be AGM assessed this year they will be trialled in the future in recognition of their importance and popularity. This year visitors to Wisley will still be able to enjoy the wonderful spectacle of dahlias in full bloom as a wide range of AGM dahlia varieties will be showcased in the Hilltop borders later in the year. Dahlias will also take centre stage during the annual RHS Garden Wisley Flower Show (6-11 September). Last year more than 100 exhibitors competed for the top prizes in the NDS competition."
NDS representatives said the move is sad but pointed out that there are many other herbaceous plants to trial while other permanent trials of plants such as iris, delphinium and sweet pea have also gone. "I was a bit upset when they disappeared," added vice-chairman Dave Bates. "We're looking for the best shop window for dahlias and Wisley certainly gave us that."