My lemon tree has much new growth and many new buds and tiny lemons. The lemons have not made it past index finger size before they drop off! some are on the ground, but not all of them could they be eaten by birds. I don't see any pesy around. Anyone know why my lemons are dropping like flys??? I am in sierra Vista AZ. I know the evevation is quite high for growing lemons. (about 4,500 ft) Any ideas or suggestions? Thanks!