when is the best time to start restocking the pond with weed and what type please?
I'm in South Devon too Gordon. Do you mean oxygenators? Most of them die back in winter, so I would leave it till the water warms up in the Spring - but I'm not an expert. My water lilies are now dying back and the fish are now deep down so I leave them to it from now till April. Try Googling 'when to stock pond with pond plants'. Lots of information there.
Tricia