Fertilizer is essential for plants because it provides vital nutrients that are often lacking in the soil, ensuring optimal growth and development. Plants require a variety of nutrients, including nitrogen, phosphorus, and potassium, which are crucial for processes such as photosynthesis, root development, and flowering. Fertilizers replenish these nutrients, promoting healthier, more robust plants and enhancing their ability to resist pests and diseases. Additionally, the balanced nutrient supply from fertilizers can improve soil structure and increase the efficiency of water and nutrient uptake. By supplementing soil with the right fertilizers, gardeners and farmers can achieve better yields, vibrant blooms, and overall more resilient plants.