I'm afraid that to be able to offer suggestions for your peach tree problem we need to be able to diagnose it. That takes more information.
Can you post a picture of what the leaves look like?
You didn't say where in the world you and your peach tree are. Where are you and what is the weather like there? Is the tree is in full sun? Any other conditions affecting it?
But in the meantime I did look up this article for you, in case this is what you are talking about (are your tree's leaves "red and warty"?)
here's a nice general article about organic treatments of plant diseases
Peach tree leaf curl: This is a common disease of peach trees. Sprays of horsetail tea, garlic (look further down the page for recipes) and seaweed can help to prevent this problem. Growing chives underneath them also helps.
Let us know if this peach leaf curl disease is even what you are talking about!