Mr Cull made the call on Friday, describing the actions of businesses that sell synthetic cannabis products like K2 as ''gross irresponsibility'' not welcome in the community.
Most mayors were aware of synthetic cannabis causing problems in their communities.
Clutha District Mayor Bryan Cadogan ''fully supported'' Mr Cull's stand, and the idea of people boycotting shop owners who sold the legal highs.
He said such pressure could make a difference. In 2011, dairies in the Clutha district stopped selling another form of legal high, Kronic, after Mr Cadogan threatened to sit outside any shop selling the product.
He realised it would be more difficult to stop all shops in Dunedin from selling the drug, due to the number of shops, but hoped some would have a change of heart after Mr Cull's comments.
''I can see that the discussion is building and I would like to think the heat gets too hot for a few of these shop owners.
''As a society we have the ability to stop this. We don't have to wait for the Government to do it,'' he said.
Despite no shops selling the legal high in the Clutha district, there was still a problem with K2 in the district, as people found other ways to get the drug.
Waitaki Mayor Alex Familton said in the past nine months he and Rev Wayne Healey had visited all outlets in their district, making it clear selling synthetic cannabis was not supported.
''We have made the community's feelings very well known to them.''
The reaction from some business owners was that it was a legal substance and they made a lot of money from selling it, he said.
''It really hinges on the Government getting the legislation right. Until that happens vulnerable people are put at a severe disadvantage.''
Central Otago District Mayor Tony Lepper ''totally supported'' Mr Cull's move.
''That is a fantastic idea.''
He had heard stories from parents who had children using synthetic cannabis.
''It's horrible, changes their mental state. I wish people wouldn't sell it.''
Queenstown Lakes District Council Deputy Mayor Lyal Cocks, of Wanaka, also supported Mr Cull's stand.
''I don't think there is any need for this product and I would support people staying clear of retailers taking the liberty of selling it,'' Mr Cocks said.
Mr Cocks was not aware of any shops selling K2 in Wanaka.
Star Trust spokesman Grant Hall, a lobbyist for synthetic cannabis, said calls to boycott the product, from people such as Mr Cull was a ''kneejerk reaction''.
''There are thousands of local Otago people enjoying this product daily without any issue or incident.''
Despite negative media publicity concerning synthetic cannabis, retailers had reported no reduction in sales.
