Peach tree--fruit gets brown spots
I'm not much of a "green thumb", so perhaps I can get some advice and guidance regarding two peach trees that are on my property (I live near Chicago). I have lived in this house since 2008 and the trees, which seem to be older trees, did not produce any decent fruit the first two summers I was here. Last year I pruned a lot of dead branches in the spring and it really seemed to help. I got a lot of blossoms then a lot of fruit started growing. Around the end of June the peaches developed small brownish-grey spots all over the fruit. They kept growing but toward the end of July they just died off and dropped to the ground without ripening.
I was only able to harvest less than 10% of what started growing.
Any suggestions? I had pounded in some Jobes plant spikes for trees a couple of weeks ago, and I see the blossoms starting (it's been a very cold spring in Chicagoland so everything is late in blossoming this year). Can anyone recommend fertilizers or sprays that may prevent this fruit from going bad?
Thanks in advance for your help.