Master Gardener: Why oranges may turn sour after pruning

Q: I had an orange tree that has always produced delicious oranges. In the last few years, it has gotten too big for my yard, so I pruned it way back, hoping that it would stay small. It seemed fine and produced lots of pretty oranges, but now they all taste horrible! What happened?
A: Oh, dear! I think you may have pruned all the grafted part of the tree away. Most citrus trees are grafted onto a hardy rootstock. This is done because most citrus roots are kind of wimpy – they are prone to