To help them win a community garden set, they're asking Newcastle residents to hand over their old toothbrushes, toothpaste tubes and floss containers and vote online for their school.

Caroline Smith, who co-leads the Sustainability Group at Newcastle High School, said the school is on a mission to recycle as much of their waste as possible and win the garden set for the students.

"Recycling and gardening are extremely important to our school and a very dedicated group of students who have formed their own Sustainability Group," said Mrs Smith.

"We have over eight different recycling programs operating in our school and all are very successful.

"Our Sustainability Groups' passion is to share and implement these recycling initiatives and create beautiful gardens made from many recycled items for the students, staff and visitors to enjoy at our school."

"The highlight of our journey in the Colgate Community Garden Challenge is our excitement when we have collected another shipment of items ready to send to TerraCycle. We collect on behalf of local offices, staff lunchrooms, feeder schools, our family dentists, retired teachers, volunteers and of course our students, staff and the wider community to all work together," adds Mrs Smith.

Run by Colgate, Chemist Warehouse and global recycling pioneers, TerraCycle, the Colgate Community Garden Challenge invites all pre, primary, intermediate, special and secondary schools in Australia to register, collect and ship all their oral care waste to TerraCycle who will turn it into new products.

A total of five schools will win a community garden set - three schools who collect the most waste and earn the most votes online and the other two winning schools will be drawn from a prize draw.

There will also be seven monthly prize draws awarding the monthly winner with 60 up-cycled pencil cases (valued at $340.80).

Schools who sign up late still have a chance to win as long as they send in at least one shipment between now and September.

Newcastle residents are encouraged to drop their used oral care products off and vote for the school online at terracycle.com.au/colgategardenvoting.