The original owner and manager of the Switched On Gardener chain of stores have lost their appeals against their jail sentences.
In 2012, Michael Quinlan was jailed for four years and three months on 16 drug-related charges. His manager, Peter Bennett, was sentenced to three years and nine months jail on 17 counts
The men launched an appeal against those sentences, arguing they were inappropriate.
Quinlan argued that the trial judge did not properly assess his culpability.
But judges in the Court of Appeal said the business aligned itself with the cannabis industry. They said Quinlan exploited that connection in all facets and they could not accept he was merely negligent.
The judges said they are satisfied with the jail terms Quinlan and Bennett received.
