A tangerine tree is actually a type of mandarin tree; the "Clementine" variety is one of the most popular grown. A tangerine tree is generally cold hardy to zone 9; however, some varieties are hardy to zone 8. In areas where freezing temperatures are an issue or a possibility, they need some cold protection to thrive.
Water a tangerine tree with about 2 inches of water every two to three weeks. However, for the first year, you should water a tangerine tree with 1 inch of water every two to three days for the first two weeks, then once a week thereafter.
Maintain a bare, 1-foot diameter around a tangerine tree. Do not allow weeds or grass to grow. They will compete with the tree for valuable water and nutrients. Do not mulch tangerine trees.
Fertilize a tangerine tree three times a year in the early winter, mid-spring and early fall. Use a fertilizer labeled 20-0-0. Apply as many cups of fertilizer as the tree is in age--split among the three different applications. For example, a three-year-old tangerine tree should be fertilized with 1 cup of fertilizer at each of the three applications (totaling 3 cups for three years old). However, the first year, do not fertilize a tangerine tree the first time until new growth appears (with 1/3 cup of fertilizer).
Protect a tangerine tree from cold injury. Loosely cover young tangerine trees (younger than four years) with a plant blanket or tarp when temperatures drop below freezing. Also, during the winter, usually from November until February, build a sloping soil bank around the trunk of your tree several feet high. You can also use a tree wrap for the trunk during this time.
Prune only damaged limbs. Tangerine trees do not need regular pruning. Make a clean, sharp cut with lopping shears within 1 inch of the parent branch.