Why don't my pecan trees produce any nuts?
When I look up the minimum seed bearing age for pecans in the Woody Plant Seed Manual it says it takes 10 to 20 years. So you may start getting flowering and fruiting soon. That is the age if the trees were grown from seed. If you planted trees that already were a few years old from seed then that would take off a few years. The best way to cut the time to fruit production (not just for pecans) is to plant grafted trees. The shoot (top) part that is grafted onto the rootstock already is advanced in age because it is a twig cut from a much older tree. So it bears fruit right away or with little delay.