How old can a seed be before it is too old to be planted?
What is the best time of year to plant the seed.
Calhoun County Michigan
Peach seeds differ greatly in how long they remain viable. Properly cared for, some peach seeds will still germinate after several years of storage at room temperature. Typically, after 1 year the ability to germinate declines. Pits that show signs of mold in storage tend to do poorly.
Peach pits normally need a cold treatment (stratification), either by going through the winter outside or in a refrigerator for several months in order to germinate normally. Planted outside you have to protect them from ground squirrels.
You can find quite a lot of information about growing peach trees from pits at the following link: