Nevermind. I figured out you have to dig a hole first with the hoe to plant a seed. It is working. You might want to explain this in the description. Nice game by the way.
Edit: What does the watering can do?
Ah I am sorry for the confusion, I will update the how to play section to explain the mechanics of the game better thanks for the suggestion.
The watering can increases the overall multiplier of your farm when you use it on a plant. When the multiplier bar is full all of the plants will provide double borophyl.