These sorry specimens are courgette plants (zucchini) which were grown from seed and transplanted to this here Growbag thingy a month ago. They've been watered regularly and kept in a sunny position but I failed to take sufficient preventive measures against snails. I prefer an organic approach to snail removal rather than chemicals which might poison the birds as well. Usually whenever I spot one I pick it up and throw it over the hedge where it can take its chances with the traffic. But the buggers have been too shrewd for me on this occasion and have made short work of these wretched plants. I'll see if I can restore them to health but I'm not optimistic!
Meanwhile, behind the courgettes is a blackberry bush in a similarly miserable condition caused not by snails but by starvation as a result of competition from our neighbour's variegated dogwood tree which he has planted too close to the fence. I'll wait till the autumn and relocate it.