I like this game. I think this is an interesting take on strategy gameplay, and once I understood the gameplay better I liked the day preview feature as an idea, as well as the way each spell has an area of effect.
I never quite figured out how to use stones or if they are a good weapon to choose. I think it would be neat to see the weeds grow in the preview window as well! (as they would if you had no affect on them. I feel like that might add to the overall strategy and theme. The game is still somewhat self explanatory, so I think you have made a pretty intuitive design.
I think the game needs some onboarding to explain the mechanics by showing rather than telling, one at a time, but for the time allotted this is really amazing!