"On behalf of Kuranui parents, I would like to thank those responsible dairy owners who have refused to sell these products.
"As a community we should work together to encourage all retail outlets to stop selling these harmful substances."
Mr Shepherd is keen for parents to be open about the problem. "Parents, please talk to your children about the very real dangers synthetic cannabis poses to them and encourage them to make safe, sensible decisions."
Mr Shepherd is organising a high-level meeting of community leaders in the next few weeks to discuss how to tackle the situation.
The Psychoactive Substances Bill will automatically ban dairies, service stations and grocery stores from selling synthetic cannabis and other legal highs.
All other shopkeepers will need a licence to sell designer drugs under the bill, which is expected to force most of the controversial products off the shelves within the next few months.
Police, courts, doctors and parents have blamed the drugs for a national outbreak of crime and anti-social behaviour, including violence, psychotic outbursts and rapid addiction similar to methamphetamine use.
But under current laws, the Government has been powerless to stop their sale, as manufacturers can rapidly change the chemical formula to get around each new ban.
The law change - originally planned for August 1 but now expected to be weeks earlier - will force drug makers to prove their products are safe before they go on sale.
The immediate effect will be that most drugs can no longer be sold but in a few years, some may pass the rigorous tests and become legal. Additional reporting, NZ Herald