I must admit that the main problem I’ve come across with growing courgettes has been too many to eat through rather than the plant itself failing.
Because they are so productive, they really do need feeding well to give of their best. I’ve tended to dig a hole and fill with good quality compost before planting on top. In this video, gardening expert Sam Youd, head gardener at the famous Tatton Park Gardens, develops on this.
Courgettes, when young, don’t like having their feet wet. Too much water and they have a tendency to rot off. On the other hand, when they’re producing fruit they need quite a lot of water.
Sam has, of course, the answer to this problem of providing the right level of water at the right time.