The HTA Catering conference saw 250 people attend to discover how to improve their garden centre catering but heard consultants warn their cafes must keep their individuality.
Turpin Smale consultant Chris Brown said: "You had such charm when you were in your polytunnels but so many places look corporate now."
HTA director Carol Paris said the £200m sector was a footfall driver and "you have to differentiate - there's a lot of competition out there".
Blue Diamond managing director Alan Roper cited HW's story last week about The Garden Centre Group's plans to bring in branded coffee outlets, adding: "There's indigestion at over-exposed brands."
But new TGCG food and beverage director Jason Danciger responded by saying that brands such as Costa and Starbucks are "fantastic" and "draw people in".
Consultant Salim Sajid said: "Dobbies and TGCG are going to fundamentally change garden centre mainstream retailing and leave a huge vacuum for independents to differentiate their offer."