Tangerines (Citrus reticulata) grow on small evergreen trees that have a dense, bushy growth habit. Tangerines grow in the warm climates of U.S. Department of Agriculture plant hardiness zones 8 through 11 and are also called clementines, mandarins and satsumas, depending on the variety. Prune tangerine trees just after the fruit has been harvested, but before the next cycle of flowering has begun. This is usually in late winter or early spring, depending on the variety of tangerine.
1. Basic Form
Tangerines flower and fruit at the tips of the growing branches. So, any pruning means removing the fruiting parts of the tree. But you still need to prune sometimes to develop a good form and branch structure. Remove any sprouts that grow from the base of the trunk as soon as you see them, at any time of the year. These sprouts will not produce fruit. You may also prune to control the height of the tangerine tree to make harvesting easier.
2. Branch Structure
Tangerines have a dense, bushy growth habit that shades the trunk of the tree. This is a natural adaptation to prevent sun damage and you shouldn't interfere with this too much. If fleshy green sprouts emerge vertically from the interior branches, you should remove them. These are called water sprouts and they sap energy from the tree, while producing no fruit. It can also be helpful to cut back the ends of low-hanging, horizontal branches by about 25 percent each year. The floppy tips can become so laden with fruit they cause the branches to break.
Cut out any dead or diseased wood as soon as you notice it. Because it is likely to harbor pathogens, remove this wood from the area immediately. Because tangerines are highly susceptible to freeze damage, inspect your tree after heavy frosts and remove any dead branches. In trees that are suffering from fungal infections, like the black mildew that is common in citrus, it can be helpful to thin out some of the branches to increase air flow to all parts of the tree.
On their own, tangerines will naturally form branches low to the ground and take on the shape of a large shrub. If you want it to have a tree form, prune off the lower branches to a height of 3 feet or so, in what is known as a "standard" form. If you wish, you can also prune tangerines into a hedge form. You won't get much fruit with this form because you're constantly shearing off the fruiting branch tips.