Lovely, cozy theme! I like the mathematical nature of all the plants' requirements, so I could plan around, for example, being able to place a lot of fibonacci sunflowers right at the end.
Some slightly clearer visual feedback could help. At first, I was just single-clicking on the plants and wasn't sure why anything was happening. It's also pretty hard to tell when a plant has been sufficiently watered, especially when the sprout is covered up by other plants.
My end-game screenshot ended up being too big to upload in a comment (>3MB). But rest-assured it looked sweet!