Well if you want my 2 cents
1. add some soundFX (unless they just bugged out on me) - I made the same mistake with my first game
2. have the plants not just differnt times to grow but also different multiplyer for how much you earn - more expensive takes longer but gives like 2,5 times - so you have not only the cost but also the time to consider for your best option
3. another shop with tool (add growthspeed multiplyer if you first treat the soil or groth burst if you water the plants)
4. add another shop with electric stuff like different growlights(colourcoded) for different plant
5. add a "bedroom" whith a desk where you can research plants so that you have a little spreadsheet that gets filled in (that lights helps that plant but hinders this other one - that plant needs more water and that one dies if you water it too much...etc you get the idea)
just of the top of my head
check out my game ;-) and leave me some comments and critiques