10 year old tangerine tree has never bore fruit
I have a 10 year old tangerine tree, but it has never bore fruit. Do I need a second tree for cross-pollination? The tree appears to set fruit after blossoming, but the fruits don't develop.
Start by checking the care your tree is getting: https://www.gardeningknowhow.com/edible/fruits/tangerine/tangerine-tree-care.htm
If you don't see anything here that rings bells, this article on orange trees that flower but don't fruit is also applicable to tangerine: https://www.gardeningknowhow.com/edible/fruits/oranges/no-fruit-on-orange-trees.htm