We did have a separate fenced & walled-off school garden-the only place on the premises you would see a green thing that grew out of the ground. But grass, unknown, rumoured it existed elsewhere in SE10, but never proven!
The front & back end tarmac areas, much smaller than the two side areas, and the other side area were for juniors & not segregated. We were just warned not to be knocking smaller children or girls over as we played football up & down the slope, or else.