Originally posted by DivineEvil:

I've seen that issue only for Birch so far, and it is a tree you'd want to plant purely for aesthetics. Oaks, on the other hand, are go-to for farming Fine Wood, and seem to give up to 3 seeds from a fell tree, so unless you're fantastically unlucky, it is possible to cultivate dozens. Just make sure you space them charitably to avoid saplings from withering.

Are you saying thati was just extremely unlucky to not get a single seed from like 20 oaks?

That´s not how this works. Or are you maybe mixing up oak and birch here? But even birch doesn´t give seeds with every tree.

My guess is you play modded. In vanilla only the beech is giving out more seeds than you need for a tree farm.