How did you start/sprout the acorns? We came home from Texas with some pin oak acorns - really small, and a super large acorn, have not tried to identify it.
looked up on the internet how to do it. lots of info, generally, put them in water, if they float, throw the floaters out. There are some other pointers to recognizing a potentially good acorn.
then, simulate winter by keeping them in a bag of moist potting soil in the fridge for three months. Did so, took them out of the fridge in the same bag, added some moisture, laid the bag on a flat surface, and a week or so later my wife says, have you seen this?
This, was seven sprouts in the bag of fifteen or so acorns. the only thing I did not do was the water test initially. transplanted them into cups with drainage holes, and a week later they were up with two leaves. now have four leaves.
Greenhouse guy says get them outside for more sun and acclimated to cool spring. have not done that yet. need to protect them from deer, bunnies, squirrels, birds, etc. plus in the warm sun all day they will need more attention with water. probably need re-potting at least once more.