Well there is no much i can say, the idea is great and i cant say much things that are not obviuos like have to work more on the scene and sound for example, also i saw the threes dont have colliders and their textures are to brigth and smooth.
Maybe one good idea will be to put a minimap with alerts, a plant healty can be green, a plant what it needs atention will be yellow and a red plant what needs atetion now.
Also a encyclopedia could help a lot to understand what things do you need to do something and how much of that you need