Hoes should work on blocks with plants on top

It's possible to use a hoe on a block to turn it into farmland, then place plants like flowers or saplings on top. However, placing flowers/saplings, etc. on top of a dirt/grass block and then attempting to hoe said base block does not work at all, despite the fact that this won't be creating any invalid states. I suggest that it should still work if such blocks are on top.