Something has got to my beans so I've had an early harvest, the leaves have gradually been going yellowy and the few pods which appeared seemed to be the extent of the crop. When I looked closely the bottom of the bean stalk has come away from the base and roots. I don't think rabbits could get in the bag to do this so I'm wondering if it's ants as I've seen them crawling on it. I don't even think rats would get in the bag and do it as I think I'd see the droppings.
Anyway I've pulled what beans I could (8 pods!) and they are a lovely colour. As you see there was less than a handful so I've boiled them to sample right away and they really are tasty.
My second batch, last picture, are coming along fine and I've just planted some more in the hope its not too late to get a crop.