So I took the peach tree back to the nursery

[XemaSab]

They gave me a new tree with little peaches on it. :D

[LiberalEsto]

1. A suggestion

The tree will develop stronger roots if you sacrifice this year's crop of peaches by removing them. Leaving them on means the tree will put all its energy into the peaches, leaving very little for root growth. The tree goes into survival mode from the shock of transplanting.

It's similar to the practice of pinching off the flowers on a plant you've just bought and transplanted into the garden. Yes, you lose the instant impact of those first flowers, but in return you get a stronger, healthier plant.