Benn Curran-Nicholls died at Royal Manchester Children's Hospital
He said: "Benn ate some yew tree berries and also some of the leaves.
"Benn’s father was not aware of the poisonous nature of yew tree berries/leaves, and so took no action.
"Interestingly neither was, in his evidence to me, Manchester City Council’s Neighbourhood Manager for Environmental Health aware that yew trees were poisonous.
"No consideration had been given to putting up notices warning of the poisonous nature of the yew tree, and risks of eating its berries/leaves – neither at the entrances to the parks nor at the trees themselves."
Most parts of the Yew tree (except for the bright red arils) are highly poisonous to mammals when ingested because they contain toxic compounds called taxines.
Eating even a few berries or leaves from the yew tree can lead to death.
After the tragedy, health and council officials discussed putting signs in the park but feared it could lead to suicidal people eating yew berries. But in his ruling, Mr Bridgman urged a rethink.
The coroner said: "The decision was not properly and fully thought through."