They broke into Aultmore Primary in Wellhouse, Easterhouse, and smashed a special bottle greenhouse and willow dome pupils had worked hard to create.
They snapped the timber frame and threw bottles around the school playground and then ripped out parts of the willow dome, which is at the back of the austism unit.
Mark Smith, who teaches primary 6/7, said: "Our primary seven pupils worked for a year to plan and co-ordinate the building of the greenhouse and willow dome.
"Teachers and parents also gave their time to make sure this all came together and then, a week after it was finished, we came in to find someone had kicked it apart.
"To say the children are upset and angry is an understatement."
Aultmore Primary is a mainstream school, but it has a unit for children who have autistic spectrum disorder.
Mainstream pupils and youngsters from the unit worked together over a year to develop the garden as part of their outdoor learning.
The school was used as a flagship for Glasgow City Council and Glasgow Life's outdoor play strategy due to its excellent outdoor learning.
Pupils gathered plastic bottles for the greenhouse and wrote letters to local sawmills to ask for donations of timber.
But when none agreed to donate the youngsters sourced quotes for wood and then raised funds for the cash to buy it.
Mr Smith added: "We were amazed at how well the children worked together and how settled and content they were in their work.
"Even the children with behavioural issues took part and enjoyed what they were doing – we just sat back and let them get on with it.
"They put everything they could into the project, which makes it all the worse that this has happened."
Mr Smith said a gang of youths was caught on CCTV camera in the front of the school and it is suspected they were responsible for the damage.
Now the pupils are working to raise money to rebuild the structures and are appealing for help.
Mr Smith added: "With Aultmore being a new school we were looking forward to building outdoor things that would be used for years to come by younger brothers and sisters and new pupils.
"We are going to rebuild the greenhouse and willow dome and we would take any offers of help to replace our broken timber.
"It is very disheartening to see a lot of our pupils' good work destroyed due to a few thugs."
Just yesterday the Evening Times told of the Love Milton Community Garden in north Glasgow, which was targeted twice in three weeks by vandals.
Yobs set fire to a shelter that contained equipment, including a mower and strimmer, and other items on the site.
The cost of the repairs will be thousands of pounds.