Espoma Organic Citrus-Tone for Citrus and Avocado Tree Food, 5-2-6 Fertilizer is ideal for citrus, fruit, and nut trees. It delivers balanced nutrition to your plants and can be used all year long The 5-2-6 NPK formulation, plus 5% Calcium, is uniquely formulated to enhance the performance of Citrus Trees. Espoma is a leader in Organic Tree Fertilizer since 1929. The Espoma Company has always been committed to the environment and sustainability and we continue to look for ways to reduce our carbon footprint.