Vendors are being encouraged to keep a tally of the number of plastic bags that they have stopped from being used and the winner will receive a gift basket of plastic alternatives at the end of the month.
Market manager Carol Tracey said it would be hard for the market to go without plastic for the month because people want their fruit in bags. She thinks going plastic-free is a good idea but notes that practicality wise using paper bags will be hard.
She believes in recycling and that people need more encouragement to recycle.
"The world needs to be more careful with its resources."
Ms Gregory hopes that many people will get involved in the challenge and that those in the north will become more conscious consumers.
"We need to be asking ourselves 'do we really need that bag?'"
A strive for a plastic bag-free Kaitaia is being driven by Ms Gregory.
There are plans for a movie night and discussion in Kaitaia during the month where films about plastic use will be shown.
Anyone can take part in the Plastic Free July challenge even if it's just stopping the use of 'the big three': plastic bags, water bottles and takeaway coffee cups. For more check out www.plasticfreejuly.org.