The best thing I can teach the children about growing vegetables is how to water them. This is an area that people do get very wrong and then do not understand why the plants do not produce anything. The same thing happened to me a few years ago in the fruit cage, I under watered the plants and the fruit did not develop well. It does seem to be a job that people feel bad about spending time on and so rush it, I have seen it many times. Spending the time watering also gives you a good chance to have a look how your plants are doing.