Fertilizing

Fertilizers are the elemental nutrients citrus trees need to grow and produce fruit.

"NPK" (Nitrogen, Phosphorus, and Potassium) are the 3 macronutrients used most by plants. Numerically represented as a percentage on the fertilizer package label.

Nitrogen is mainly used in growth

 Apply a fertilizer with equal NPK or a higher ratio of Nitrogen to phosphorus and potassium in the spring to promote plant growth. Use a fertilizer with a higher ratio of phosphorus and potassium to nitrogen in the winter or before plants flower to improve yields. Use 8-4-4 every 3 months from spring (March-April) through the fall. Use 3-12-12 Harvest Booster before plants flower or during winter dormancy (December-January). Apply 1 cup (150 grams) for every 1-inch diameter of the trunk, for a 15-gallon size. Apply 2 cups (300 grams) for every 2-inch diameter of the trunk or 25-gallon size. 

To apply fertilizer, till the top layer of the soil to create a ring/berm/wall around the trunk. Spread fertilizer above the roots, avoiding the trunk, and provide water to incorporate the fertilizer into the soil.