|Sour orange rootstock that took over a Navel Orange tree|
Q. I have a dwarf tangerine in a container that gives lots of fruit but it is sour. Why?
A. Sugar content is developed over time as fruit matures. When the fruit is immature it usually has higher acidity and low sugar content. As the fruit matures the acidity drops, and sugar content climbs. Be sure to wait for full color development in the fruit and it should be at its highest sugar content.
Tangerine is sometimes grafted onto sour orange rootstock. If the tangerine part of the plant dies, the sour orange rootstock will replace it producing beautiful fruit but very sour and it will never become sweet. If this is the case, and this happens a lot in Las Vegas due to our winter freezes, dig it out and replace it.