The dwarf Algerian tangerine fruit’s greatest virtue may be that its thin, red-orange skin practically falls off into hands eager for the succulent, sweet fruit inside. Commonly known as clementines and mandarin oranges, standard Algerian tangerine trees (Citrus reticulata "Clementine”) stand up to 25 feet high. Grafted to dwarf rootstock, they reach no more than 8 feet. In-ground plants in U.S. Department of Agriculture plant hardiness zones 9 through 11, they grow elsewhere as container plants that are overwintered indoors.
The first Algerian tangerine tree reportedly appeared in 1902 in the garden of the Peres du Saint-Esprit orphanage in Misserghin, Algeria. Father Clement Rodier came across the chance hybrid among a group of other mandarin seedlings. Louis Trabut of the Algerian Botanic Garden, highly impressed with the tree's early ripening and distinctively flavored fruit, named the cultivar "Clementine" in Rodier's honor. U.S. Department of Agriculture botanist Walter Swingle took "Clementine" bud-wood -- actively growing shoots ready for grafting -- to Florida in 1909. In 1914, the cultivar was taken to California by Howard S. Fawcett of Riverside's Citrus Research Center. The introduction of citrus-dwarfing trifoliate orange (Poncirus trifoliata) rootstocks for grafting led to the 1950s commercialization of dwarf Algerian tangerines.
Standard-size Algerian tangerine trees have spreading, rounded canopies of willowy, sparsely thorned branches. Their clusters of fragrant, white, spring flowers open against dense, deep-green, lance-shaped or oval leaves. Their sweet, seedless or lightly seeded fruit typically measures less than 2 ½ inches in diameter. Its loose, thin skin ripens to a rich red-orange in late fall and early winter. Dwarf Algerian tangerine trees share these ornamental characteristics, including evergreen leaves and full-sized fruit.
Dwarf rootstocks play a critical role in the ultimate size of a mature Algerian tangerine. Trifoliate orange and its hybrids are common dwarf rootstocks. "Flying Dragon" trifoliate orange rootstock produces grafted trees 20 to 30 percent the size of standard Algerian tangerine trees, or 3 to 5 feet tall with 14-inch to 3 1/2-foot spreads. Occasional pruning maintains the slowly growing plants as bushes or small trees ideal for sunny indoor spaces and small patios and decks.
Dwarf Algerian tangerine trees thrive in sunny, well-drained locations with sandy soil and acidic soil with a pH of 5.6 to 6.5. Consistently saturated soil exposes them to iron deficiency and root decay. Slowing watering to a depth of 3 feet every two to six weeks during dry weather is best for these trees. Nitrogen-phosphorus-potassium (NPK) fertilizer with a high concentration of nitrogen applied in equal amounts in early February, mid-March, early May and mid-June keeps the trees vigorous. As outdoor container plants, the dwarf trees perform best in sunny, wind-sheltered spots and a well-draining potting mix. Dwarf Algerian tangerine trees that are overwintered indoors need a south-facing window, daily misting and cool temperatures.
- Missouri Botanical Garden: Citrus Reticulata "Clementine"
- University of California Division of Agricultural Sciences: The Citrus Industry, Revised Edition, 1967, Vol. 1; Robert Willard Hodgson et al.
- Florida State Horticultural Society: The Breeding Behavior of the "Clementine" Tangerine; P.C. Reece and C.J. Hearn
- U.S. Department of Agriculture, Agricultural Research Service: Immigrants
- University of California-Riverside, College of Natural and Agricultural Sciences: Flying Dragon
- Four Winds Growers: History -- Dwarf Citrus Trees
- 1979 Sunset New Western Garden Book; David E. Clark
- Alabama Cooperative Extension System: Citrus for Southern and Coastal Alabama
- Growquest Nursery: Clementine Tangerine Tree