Q: My two Japanese maples have been growing in these pots for ten years. They have slowly declined each year. They lose leaves very early in fall and they each have small limbs that die every year, a little at a time. Is this a symptom of being root bound?
A: I think the pots are simply too small for the trees. Unless you are really good with watering, the soil becomes dry after just a few days in summer.
Fluctuating moisture then causes leaf drying and subsequent limb death. I recommend you move the trees up to pots at least twenty-four inches in diameter. With appropriate watering, I think the trees will be a lot healthier.