At one time my garden was full of vegetables of all types. Yet in recent years vegetables do not grow there. Even carrot seed does not lead to carrots. I have ended up growing only flowers. But this year even they are not doing well. My dahlias are growing decently but producing no or almost no flowers. I planted two cherry tomatoes from a nursery this year and the plants are 2 m tall but generating only a couple of tomatos. I assume that some essential nutrient has been used up over the years. Does anyone have any suggestions?