What fertilizer is best for tomato plants?

Tomatoes need different nutrients at each stage. Seedling to transplant: balanced NPK 19:19:19. Pre-flowering: high phosphorus (12:61:0) to promote root and flower development. Fruiting: switch to high potassium (0:0:50 or 13:0:45) for fruit size and flavour. Organic options: banana peel water (potassium), fish emulsion (nitrogen), bone meal (phosphorus). Avoid excess nitrogen during fruiting — it promotes leaves over fruit.