Badly treated leaves!

I have 2 cobaea scandens growing in pots in the greenhouse. I bought them last summer to cover the bean poles when I thought the beans had failed utterly. But they recovered before the cobaea were big enough to plant out. So here they still are. One of them, whose roots have escaped into the earth, seems to be dead. This is the other, in a smallish pot, hardly watered, and such a lovely colour. Death song, I expect!