Tangerine Trees

I'm unfamiliar with Citrus Fruit, but a little information digging reveals that the Tangerines' Latin name is - Citrus reticulata, synonym Citrus X noblis - which as well as Tangerines it covers Mandarins & King Oranges [ now,I've never heard of King Oranges before this particular 'dig' ]   The info. writes that -  "This is hardiest of the species, bearing narrowly ovate to elliptic or lanceolate leaves;clusters of white flowers flowers , about 1 in.wide, are produced between April and June. The round orange fruits, with wrinkled loose skins, are 2-3in. wide.

Cultivation - Grow citrus plants in 8-10 in final ( home) pots or small tubs of John Innes ( soil-based ) potting compost No.2. The plants dislike root disturbance, and so potting-on should be carried out during the  (dormant) winter months.Once the plants are in their final containers, remove the top / surface  2 inches of the compost annually in April ( Spring ) and replace with a 50:50 mix. of loam and manure.     Keep the plants only-just moist in winter, and water more freely in summer: mist-spray the leaves daily in hot wether and shaded the glass lightly.     During summer, ventilate the room freely and stand the pots in a well-lit position;they may also be temporarily plunged outdoors into full sunshine from Mid-June til late September.  Provide an average lowest  Winter-Time temperature of 45 degrees , with a preference for a minimum Winter-Time temperature of 55 degrees.

Pests - Scale. Inspect regulary.

Pruning - NO regulat pruning is required, BUT all growths may be ahortened by two-thirds every third year - in late winter/early Spring. to keep it shapely.

Additional help?   Well I do know they grow them successfully in California.  You could ask a grower .