here are 2 ideas i have had--
#1
once your tree dies in graal--it is worthlis. i think you should make-Fertilizer-- so once it dies you can put Fertilizer on it so it can grow again from that stage.
#2-the funny one
Money Tree-pay apples and get seeds- plant trees like apple trees but they grow Gralets- 30 apples(30 apples=60g)buys 5 seeds each - tree can grow 100g to 150g.. but takes long time-just like apple trees;
sorry about the spelling problems if there are some!