It would be great if it was clear how often you need to water trees and how long it takes for them to grow. I planted two beans yesterday in my backyard, and they were seedlings when I left the game. Now, less than a day later, I logged in to find that they have disappeared. Based on the feedback I got on the Help Chat, I assume they died.
It would also be nice, when they die, to see evidence that they existed (i.e., dead plants). We could click on the dead plant and see why it died (for example, it needed water 10 hours ago and didn't get any).