Following the successful construction of a garden bed in another part of the school, the kindergarten area will now be getting a garden bed of its own - and the kinder students are helping the older kids build it.

It's all part of the lead-up to World Environment Day on June 5, for which the theme this year is 'beat plastic pollution'.

With their 'eco-bricks' - milk cartons stuffed with bits of plastic waste - the West Launceston students will line the edge of the garden bed, covering them in chicken wire and then pouring cement over them so that when the bricks eventually break down, the plastic inside them doesn't get swept away on the wind.

The idea is to reduce the amount of plastic waste going to landfill. And the students have already contained more than 70 kilograms of plastic waste by making their eco-bricks. It was inspired by similar projects in other countries, where schools, houses and outdoor furniture have been made using eco-bricks.

West Launceston Kinder students have been stockpiling the bricks since the beginning of the school year.

Oliver Courtney, a Year 5 student, said the eco-brick project was very important to the students.

"You don't know what you do with your plastic, do you?" he said. "You don't know where it goes."

"Because when it goes away, where is away?"

Oliver joked that US President Donald Trump should build his proposed border wall with eco-bricks, due to the country's notoriously poor track record on recycling plastics.

Teacher Jo Dean said it was "great that we're planning a way to be able to move forward and reduce the amount of plastic that's being produced in the school".

"It's useful from a science point-of-view as well because we're able to monitor what's going into each container and make some datasheets to be able to monitor the plastic that's within lunchboxes," she said.

"And then from there we can create a strategy to be able to reduce the amount of plastics going into lunchboxes and into the school environment."

Each classroom in the school contributes to the project.

On World Environment Day on Wednesday, the students will be visited by City of Launceston waste management educator Mary Gill, who will teach them about all the different ways to address plastic pollution and reduce the school's waste. They will also be making beeswax wraps.