They're about 3 months old and were doing really well, but recently started to develop what look like mould spores on the leaves and stem.
I washed them all down yesterday, but the mould is back already.
My other half thinks I may be over-watering them, I think otherwise. They were replanted into those pots a few weeks ago; they were brand new from the garden centre, but also need mould wiping off them every now & then; I don't know if that's significant or not.
I've attached photos. The plants are clearly ill from whatever this is.
Does anyone know what this is and if there's anything I can do about it?