What kind of potting soil did you use? How often do you water and for how long?

I am not sure now what potting we used. I was not watering the tree. I was letting it collect rain water. It seemed so happy that I didn’t want to disrupt a good thing.

*potting soil

It kinda makes a difference :-)) Most commercial bagged potting soils are peat based and excessively moisture retentive. That results in a high perched water table and the potential for root rots. A more freely draining, bark based mix would be better and allow you to water as needed without risk of the soil staying too wet.

And you cannot rely on rainwater for sufficient irrigation for anything grown in a container. It does not penetrate to the same degree as it would in the ground and often the plant canopy will deflect it away from the container soil. You want to be able to water thoroughly, so that water runs freely from any drainage holes and then wait to water again until you can determine that the soil has dried to at least the depth of your index finger. A tell or wooden probe would work even better as it can get further down into the container to measure soil moisture. You never want the soil to dry completely but you also do not want it to remain wet......consistently moist is the ideal state :)

Wow thank you so much!

Are the yellowed leaves being shaded out by the rest of the foliage? They look to be toward the bottom.

Perhaps? I didn’t know this was a thing!

It's not :-) Shading of lower stems and branches is common with most trees and shrubs. With the exception of tightly pruned hedges or conifers, it is almost never a concern.

And shading would not account for the dried and brown foliage anyway.