Healthy tangerine trees produce lots of sweet, floral citrus fruit. But unhealthy trees may bear few to no fruits and may be diseased or stuck in their containers. Move tangerine trees when their environment is hurting them and you've ruled out plant diseases. A well-executed and well-timed move should help revive the citrus tree.
Gardeners growing container tangerine trees need to move them into larger containers whenever the trees outgrow their location. Four Winds Growers recommends their container citrus trees (including tangerine) get replanted every 12 to 16 months. If not moved into a larger container, the tangerine tree suffers and declines, showing less vigor and bearing fewer fruit.
Gardeners growing ground trees may need to transplant them if the tree receives too much wind or too little sun in its growing environment, if it grows too large for the spot or if it otherwise seems to be unhappy. Tangerines (like all mandarins) prefer full sun and protection from the wind and frost and transplanting to the south side of the house provides these things. They also require well-draining soil to avoid developing rootrot.
Prepare a ground-planted tangerine tree for transplanting by watering it for three days before the move. Watering helps loosen the roots within the soil so you'll have an easier time moving the tree. Four Winds Growers recommends not watering container trees, since they pull out of the container easier if slightly dry. If you're potting into a new container, select your container and ensure it has drainage holes. If you're planting in the ground, survey the sunlight in your yard and select the best location. Texas A & M recommends planting tangerines on a level or hilly location, not in a valley. This prevents the tree from getting flooded during rains.
Process for Ground Planting
Dig the new hole before you remove your tangerine tree from its current location. As for all tree transplanting, make the hole twice as wide as the tree's root ball. GardenLine notes that a tree's root ball is 9 to 12 inches wide and 6 inches deep for every inch of trunk diameter, so use this as a guideline. Then dig out the tree, working at twice the root ball distance. Dig down and closer to the tree so you slowly gather its roots into a ball. Work until you've gathered all roots, then carry the tree over to its new location. Place it in the hole at the same depth as it was planted and fill in the hole with soil. Water the tree after planting until the ground becomes saturated. Avoid mulching the ground around your tangerine since it increases the tree's chance of getting foot rot, warns Texas A & M.
Process for Container Repotting
Fill your new container two-thirds of the way with potting soil. Then grasp your tangerine tree by the trunk and pull upward. Ideally, the tree will lift out of the soil. If it doesn't, work the soil near the top and sides of the container with a trowel, then try again. It should come out.
Place the tangerine tree in the new container so it sits at the same depth as it did before, then pour more potting soil into the container. Add soil until it reaches within 1 inch of the top of your container. Water the tree thoroughly to compress the soil, until liquid flows out the bottom of the container.
Avoid moving all citrus trees in the fall since this leaves them vulnerable during winter. Nassau County Extension recommends moving citrus trees in the spring, since this is after the winter harvest season. Spring-transplanted trees fully adapt to their new home by the wintertime so they get damaged less. Four Winds Growers recommend transplanting citrus trees in the morning with less chance of hot sun or on more temperate days, since sun can dry roots.