Question
I have an orange treee and the fruit is sour. I was told because of a frost here in Texas the tree has gone sour and can,t be reversed.
Is it possible to re graft another tree onto the rot structer as it is a fully mature treee about 12 ft. high.
Thanks  look forward to your reply
Bob

Answer
Hi Bob, The tree didn't go sour because of the frost, the orange part of your tree was killed and the sour orange is the root stock.  You could graft onto the sour orange, but I would check to see if the fruit would turn out OK.  Different root stocks could change the taste of the citrus you are putting it on.  Anyway, it can be done if you can find someone who knows how to do it.  Happy New Year, kathy