There are many varieties of mandarin oranges, and most come from smaller trees than that of the sweet orange. Mandarins have thin skins that are easily peeled and sections that readily come apart. They are sometimes referred to as tangerines, but tangerines have a reddish-orange skin while mandarins are orange. Of all the mandarin varieties, the Satsuma group is the sweetest and is almost seedless. Satsuma mandarins are also the most cold and disease resistant. Most mandarins are hardy to USDA planting zone 9, 8b with winter protection.
Create a water ring with soil in a 2-foot diameter around the tree. The ring should be 6-inches high and thick. Fill the ring with water every three days for the first two weeks after planting and allow the water to soak into the soil. Reduce watering to once a week for the next two months. The water ring will disappear into the soil.
Water the tree every two weeks throughout the growing season once the tree is established. If the soil is sandy and dries out quickly, you will need to water more often. The tree is considered established when the water ring is completely gone.
Keep all weeds from growing in a 2-foot diameter around young trees and 1 foot beyond the canopy of established trees. Mandarin trees will not compete well with weeds for water and nutrition. Hand pick weeds around young trees and use a contact herbicide for established trees. Do not allow the herbicide to touch the trunk or branches of the tree.
Apply a fertilizer made for citrus trees after you start to see new growth on the tree. Follow the manufacturer's directions as to amount to use per the age and size of the tree.
Wrap the tree in a blanket and stake the corners of the blanket down angled out if there is going to be a freeze. In extremely cold weather, make a frame around the tree, cover with a tarp and install a light bulb under the tarp to keep the tree from freezing damage.