why are my oranges so sour on top and sweet on bottom
hi my name is Josie and I live in san Antonio texas the problem with my oranges is that the bottom oranges are real delicious and big and the other ones are sour and have a bumpy skin the bottom ones are smooth I fertilize once a year at xmas when the grandboys come over so I can watch then do it I put mulch on it a couple of years ago on it but im gonna take it off since I read not to also what zone do I live in and what is the best fertilizer for it also I water it almost 3 times a week since I put the sprinkler on for the birds to bath in the 103 degree weather and then they sit on top of the orange tree and scratch my oranges which I don\'t mind cause those are usually very sour . please I need all the help I can get for next year. thanks
I suspect that the sour fruit is on a portion of the tree that has originated as a sucker from below the graft, from the sour-orange root stock, and grown up to dominate the foliar canopy. It may be too mature now to remove, but if this had been discovered earlier, you could have removed the sucker in order to preserve the desired fruiting portion of the tree.
I recommend that you have a professional arborist evaluate the situation and determine if it is practical to remove the sucker growth at this stage.