Currently, Serene season adds support for saplings by default. However, after they fully grow, the leaves bear fruit disregarding the seasons. I tried to register them manually, but it seems like this mod does not add leaves as blocks, and from apple leaves are displayed as "minecraft, apple leaves", it seems like those are just block form of each fruit (please correct me if I'm wrong, I have almost no knowledge in mod/coding).

I entered each fruit's name, but it did not work and according to serene seasons author, this can happen if those are not codded as forge crop/plants. And I think this is reasonable because fruits are not saplings...but could you allow us to add compat for tree leaves (and probably grape leaves too)?

Yes or no, thanks for this wonderful mod again. :)

Serene Seasons does work with the fruit trees, but the crop block you need to add to the config are the leaf blocks, not the fruit blocks. e.g. "simplefarming:cherry_leaves"