I just found that there`s weed mat in this garden and that could be why the gerbera plant flowers are small due to the plant not getting enough depth. Ok
Solved, dug up the Gerbera plant and there under it was weed mat, the plant shallow on top, not good. See photo, but is impossible to remove the weed mat. We separated the gerbera plant and now have six plants in different places with good depth and no weed mat.