Hi Hoemancat,
Some varieties of apples are self fertile and some aren't.* Peaches are usually self fertile.* Do you know which varieties of each that you have?* We could look them up.
*Maybe you are lacking in bees, especially if you or anyone near you sprays with pesticides or herbicides.
I'm thinking you meant to type the man suggested you swipe the tree with a board, not wipe it.**:)* The idea of whacking the trees is to make them think they are threatened or under attack or threat of death and therefore they will produce more seed.* The seeds are contained in their fruit.* The problem with that is the potential to damage the bark and expose the cambium of the tree, making a place where insects and disease can attack.* If you do hit the trees, be sure to wrap a towel around the trunk so you don't damage the bark.
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.