Containing equal amounts of nitrogen, phosphorus, and potassium, it's an ideal fertilizer applied from the base to meet the plant's NPK requirements in the early stages. Therefore, 15.15.15 compound fertilizer is a preferred base fertilizer for fertilizing citrus fruits, fruit trees, vineyards, bananas, greenhouse vegetables and ornamentals, field tomatoes and vegetables, potatoes, sugar beets, tobacco, onions, garlic, canola and leeks, cabbage, and cauliflower.