Q. I removed a diseased (clarified by saying the only problem was borers) peach fruit tree.  How soon can I plant another peach tree in the same hole? A. If this is from borers, then you can plant immediately. Not a problem with borers and replanting. The entire lifecycle of the borers in our fruit trees are in the aboveground portion of the trees, not the roots or soil.             There is a problem potentially with something called replant disease but it is minor in this case and should be not a problem for you. Remove as much of the root system as possible before planting.