Caesar told Contact 2011 delegates that locality was becoming more important to consumers and he urged growers to advertise their plants as locally grown.
He said: "Britain has the strongest gardening tradition in the world and as growers we do a good job, but we are largely anonymous and the gardening public doesn't really know we exist.
"So three years ago we put a Union Jack on our plants and got positive comments from retailers who were proud to stock British-grown plants. We now offer the locally grown logo to all customers a one-hour drive from the nursery. Our inspiration was to market the business as growing plants locally, responsibly and with local people."
He explained that it was not a case of being anti-European but a means of getting retailers and consumers to support British growers.
"The Future Foundation predicts local will be more important to the customer than organic, and it's a movement that we should be looking at as an industry," he added.
"There's a positive amount of pride in stocking British-grown plants and it's important to the grower to accelerate that."
He said growers should also be highlighting the environmental credentials of their stock, which he described as "environmentally positive products grown in an environmentally responsible way".
HTA market research manager David Denny agreed and said: "Local is becoming incredibly important and we are seeing that more in other areas of retail - it's a big phenomenon and it's playing through on the political agenda."