Too much rain will do this to a peach tree. If the tree is not in a well drained area that gets lots of sun; I’d move it since it hasn’t been in the ground long. Other issues could be peach leaf curl, bacteria spot or some type of deficiency (iron or nitrogen). It’s too late to spray for disease but you could fertilize with high N fruit tree fertilizer. most likely it is getting to much water.

Thanks for your response! Too much water, wow! It gets lots of sun, though I'm not sure how to tell if the soil drains well. Our soil is about 8-12" deep, and then there is clay. We broke up the clay a bit and added compost when we planted. It looked very healthy for a while. The other trees in our yard, while not peaches, all look great and have full, green leaves. It has rained a lot, but not a crazy amount. Just enough that I don't need to water often.

Amending the planting hole with compost in a clay based soil just creates a bucket of soggy, slow draining muck that will encourage root rots, regardless of much or how little rain or water the plant receives. You never want to amend individual planting holes for all sorts of valid reasons, the primary one being the soil interface and drainage issue. Use native soil only and apply any amendments as a top dressing or mulch. Or amend over a very wide area but never just the planting hole.

And you want to keep a decent clear area free of weeds or grass away from the base of the tree, typically a 3' diameter or a radius of 12-18 with a larger, more mature specimen.

How to plant trees and shrubs

Thank you for the response! Since the consensus seems to be too much water, what can I do about it? Should I perhaps remove the mulch around the base to let the tree dry out better? Is there a way to know if it suffers root root without digging the plant up? It seems to be in a good location, and actually we did dump a bunch of water in the hole before planting to be sure it drained. Perhaps it will naturally resolve as it rains less this summer?

I'm attaching some new photos. The bark is rather yellow in some places, and shriveled in others. Some fruits are likewise shriveled. It has lost a lot of leaves, and doesn't seem to be growing at all. I really want to save this guy! It seemed to perk up a bit after the last rain, but that was short lived.

Well I went out and pulled the fruit off the tree, and noticed a few more things I had not seen before, small red dots and a web. I'm guessing these are spider mites? Also there is some powdery white stuff in places. I suspect these are not the primary problem? This is our first Peach Tree, and we are really garden novices more generally, so I really appreciate any advice. I was really excited to plant this tree, and it's pretty depressing to think it might be a goner...