How much does this go for? It is not on the HD website. It is locally created in Florida. Three bags of wood chip mulch are what? 6 dollars? This plus some decent slow release fertilizer with micro-elements might go further on one fruit tree. Home Depot has some of these though the 8-3-9 found in PB, Broward, Miami|Dade counties is superior. But HD and Lowes have a 6-4-6 slow release w minors that is called citrus|avocado|mango fertilizer.
Then do a Patricks type foliar program or at least Southern Ag Citrus foliar (found at HD)