Four firefighters who had been watching from the station told them to "knock it off".
"They were bored basically, but it was a really stupid thing to do," said chief fire officer Mark Thomson.
He said there are a large number of residential properties bordering Stanley Park which could have been put at risk if a large fire started.
The crew spent about 30 minutes inspecting the nearby manuka trees for burns and doused small areas which the youngsters had ignited with the matches.
"We then just put a thermal camera on to make sure everything was put out properly, because manuka is very flammable," Thomson said.
He said people playing with matches or attempting to light fires was a major concern.
"Especially when there’s houses near the manuka and manuka is very flammable."
Thomson said given February’s damaging Port Hills fires, it was everyone’s responsibility to be fire safe, regardless of their age.
