Thanks very much for playing, and doubly so for such structured feedback! I'll get back to this project after the voting period ends and squash those bugs. I'm glad you enjoyed the atmosphere.
Edit: The watering can increases growth rate, and the shovel is there to let you plant the seeds! The game should be hard enough that you're compelled to have plants closer to the hill, but the fact that you didn't need it tells me there's more tweaking to be done, which is useful as well.