We have 1 peach tree which lives with our 2 apple trees. Every year (we've lived here for 20 yrs) it gets blooms on it and gets tons of peaches but just when they are starting to ripen, every one of them gets rotten places and fall off the tree. I have also noticed that the trunk of the tree always has black and green patches on it. I would love to have peaches at least 1 year. What can I do?
Sounds like your tree might be suffering from brown rot fungus or peach scab.
These articles may help you identify exactly what's going on and then choose the appropriate treatment: