When you see what you think is a peach tree spring up in your driveway, you're probably right. But you'd be wrong if you think it'll give you nice peaches. Stonefruit tend not to work that way - it's a team effort between the rootstock and the scion wood.
The good news is that if youve got a strong sapling then you have the first part. Then to just graft to the top.
Ive got one in the driveway where I've budded about five donut peaches and espaliered them, as well as putting a heritage "Giuseppe Masciantonio" on the upright. Both should give me fruit this year - I think I did them three years ago. Also a little one in the garden has only had one summer as the three year ago attempt failed. But I should get fruit on that too.
The experiment continues.