Use a fertilizer specifically for citrus plants, fruit or nut producing plants. These fertilizers have elements required for fruit production. It is also recommended to use foliar applied micronutrient nutritionals that citrus trees crave—they provide additional "vitamins" your trees will love. GrowScripts has a great nutritional that is based on what has been proven in the citrus industry. You can find more information about GrowScripts products for homeowners by visiting www.GrowScripts.com.
Newly Transferred and Mature Citrus Trees
For the first three years of newly planted trees it is recommended to fertilize from late February thru the first of October about every 6 weeks to establish a larger, fuller canopy on your citrus tree. (Note: slow release fertilizers will be less often, follow label directions.) Spread fertilizers evenly under canopy. Granular fertilizers can burn tree roots and cause issues if used to heavily. It is recommended to use a slow release fertilizer high in nitrogen and potassium as that is what newly transplanted and established trees look for most. Citrus trees are heavy feeders and can benefit from 3-4 slow release feedings throughout the suggested fertilizing months above. Along with fertilizing with a product such as an 18-5-10 Slow Release consider additional applications of Essential Micronutrient Nutritionals as their label directions suggest.
Balanced nutrition of plants should be a high priority management objective for every citrus grower. Plants require a balanced nutrition program formulated to provide specific needs for maintenance and for expected production performance. Properly nourished fruit trees or plants grow stronger, produce more consistently, have better disease resistance, and are more tolerant to stresses. Source: Plant Nutrients for Citrus Trees an IFAS published document #SL 200. First printed: January 2003. Reviewed February 2009.