Edwards, a HTA bedding group member, said: "Planteria managers don't like bedding because it is quite hard work stocking up and watering.
"But if you look at bedding turnover and what it could be, there could be a different treatment. Garden centres should look at bedding sales and understand the value."
Merchandising ideas such as selling colours together rather than species together could be in a new HTA bedding leaflet, he added.
He said of the group that its inaugural conference in 2010 was very pleasing, adding: "Bedding needs to work more nationally."