Connel said his seminar at last week's Chicago show showed that although "the US invented Christmas" UK "less is more" merchandising was the best in garden centres worldwide.
Connel said: "Consumers are being overwhelmed by choice. They are looking for the retailer to help them navigate. The UK has shown the US it is possible to take a more disciplined approach."
Connel said Garsons Farm in Esher, Surrey was "clean, commercial, shoppable and inspiring", and puts customers at ease because they have confidence that the retailer is in control.
He added that Homebase and B&Q had cut Christmas themes to around six, while some independent garden centres still had up to 80.
Connel also said the UK was also ahead of the US in grow your own. The "welly to belly" market is hot in the US, he said, but UK garden centre displays of kitchen gardening and potato bags were more innovative.
Garden designer Diarmuid Gavin, Jim Bradley from Mid Ulster Garden Centre, garden centre architect Gary Wilburn were also among the UK and Ireland contingent at the Chicago show, which attracted 3,267 buyers from 2,000 stores.
Show organiser Jeff Morey said demand for exhibitor space was 160 percent the size of last year's inaugural show.
Next year's Independent Garden Center Show returns to Chicago's Navy Pier August 18-20.