Vigilant Standtrue, 39, had previously admitted charges of assaulting the boys - aged nine, 10 and 11 - between July 2017 and July 2020.
Standtrue initially faced seven charges, however four were withdrawn and two others were laid representatively covering multiple offences of the same type.
The offending occurred inside the classroom at the Gloriavale Christian Community School, and in the community garden.
On one occasion, the teacher became angry with a 9-year-old boy involved in a treasure hunt, and threw the treasure he found in the rubbish bin.
Standtrue held the boy on the shoulders and around the neck and shook him.
On other occasions he became angry and shook the children when they pulled out yams instead of weeds in the community garden.
Standtrue also called one of the boys a "moron" and yelled at the children.
In one of the victim impact statements, a boy wrote that he was afraid of Standtrue and constantly tried to stay away from him.
At Greymouth District Court, Judge Stephen O'Driscoll said Standtrue had breached the trust of young, vulnerable children.
"You are remorseful and have started to address the issues which trigger you."
But the judge said the offending occurred out of frustration and was not premeditated. "You did not have the skills to be able to deal with the children at the time."
Standtrue had sought a discharge without conviction because of the risk of losing his teaching role at the school.
The Teachers' Council said it did not matter whether he was convicted or not as he would still be investigated. The council noted that other teachers who had been convicted in court often still continued in the profession.
Judge O'Driscoll said the council would now consider whether Standtrue was suitable to stay in the job.
Standtrue was convicted and sentenced to 12 months' supervision with special conditions.
