I have a tangerine about 12 years old in a container. It's outside in summer, indoors in winter. It has tons of flowers, buds and fruits all the time, but they're sour! What can I do to sweeten the fruit on the tree?
I'm in Charlotte, North Carolina. It's no particular variety of tree, just seeds from a tasty snack that germinated. I heard wood ash could sweeten them but had no effect. The tree is very lush and smells heavenly.