Hello Kelsie, 

Thanks for reaching out to UVM Extension Master Gardener Program.

It looks like you've got a case of peach tree leaf curl which is an early season fungal disease that prefers cool wet conditions.  The leaf curl fungus can cause damage to peach trees by causing an early leaf drop. This can weaken the trees, making them more susceptible to other diseases and to winter injury.  Symptoms can be visually striking but not very damaging to the tree. However, once you see it, it is too late to control it and typically, a fungicide is not warranted until the fall or following spring.  

If you experience significant defoliation now, you can thin the fruit on the tree to compensate for the loss of leaves. Over-cropping the tree will weaken it and make it more susceptible to winter injury.

I checked in with Ann Hazelrigg for treatment recommendations. She suggests making sure to pick up all drops in the orchard and pruning the trees well in the winter to allow good light and air penetration. Consider applying a single fungicide spray in the spring before buds begin to swell. Effective fungicide active ingredients include chlorothalonil, copper (e.g., Bordeaux mixture), and ferbam. Choose a fungicide that is labeled for use on edible fruit crops, and read and follow all label instructions to ensure that you use the product in the safest and most effective manner possible.

I hope these suggestions help. Please feel free to reach out to us if you have any further questions.

Further reading:

"Peach Disease - Peach Leaf Curl" PennState Extension - https://extension.psu.edu/peach-disease-peach-leaf-curl

"Peach Leaf Curl" Ohio State University Extension - https://ohioline.osu.edu/factsheet/plpath-fru-26

"Good Growing: Peach Leaf Curl" Illinois Extension - https://extension.illinois.edu/blogs/good-growing/2020-03-11-peach-leaf-curl

Glad to hear you found it helpful, Kelsie. Good luck! You're not alone. We've had a lot of questions about this recently.