USDA hardiness zones: 9-11.

Chill hours: None.

Heat tolerant: Yes, except for Satsuma cultivars which are unsuitable for high temperatures.

Drought tolerant: Somewhat, after three years, but not without damage to the fruit crop.

Sun: Full sun with afternoon shade when temperatures are over 90°F (32°C).

Planting: The best time to plant a citrus tree is after the danger of frost is past, in late winter or early spring.
Place mandarin trees in a sunny location, with afternoon shade, away from the coldest part of the yard, and out of the wind. Do not position the plant next to a frequently watered location, such as grass. Make sure there is enough space for the tree to grow to its full width and height, with clearance to walk around and where overhead lines will not be a problem.
Dig a hole twice as wide as the rootball, with the root crown at 1-2" (2.5-5cm) above ground level. The top roots must extend out from the trunk, just above, and uncovered by, soil. The soil should slope gently downward from the trunk to the drip line (furthest extent of the branches).
Mandarin trees can be grown in containers.

Soil: Well draining to prevent root rot. Do not amend the soil when planting. The roots will adjust to the native soil surrounding the planting hole.

Fertilize: Apply an organic fertilizer every month or two from mid-winter to early fall. Alkaline soils will cause iron deficiency. Apply a citrus micronutrient solution as necessary when leaves become yellow with green veins, signalling a micronutrient deficiency. Only use products containing iron in chelated iron form, which is more easily absorbed by the plant. Avoid chemical fertilizers because they increase salt build-up in the soil. Do not fertilize after the end of summer to keep the plant from producing new growth that will be harmed by early frost.

Water after becoming established: Basin irrigate or deep water for 1.5 hours or more until the water has reached a 3' (1m) depth. The frequency of irrigation depends on the species, the age of the tree and the month of the year. In the southwestern United States, for trees in the ground three years or more, irrigate as follows: December-February, every 21-30 days; March-April, every 14-21 days; May-June, every 14 days; July-September, every 10-14 days; October-November, every 14-21 days.
Inward leaf curling, when the leaves are uniformly green, or drooping leaves, are signs of insufficient water. Solid yellow leaves are a sign of overwatering. Do not water at the trunk but near the drip line.

Mulch: Apply organic mulch inside the drip line and 8" (21cm) away from the trunk to reduce soil evaporation and reduce root zone heat and cold stress. Place a rodent gnaw guard around the trunk at the bottom.

First Year Care: Remove all fruit, if any, when first planted. Remove all fruit developing in the first three years so the plant will direct its energy to growing roots, branches and leaves. Water at planting, then for the first month, every 2-3 days; for months 2-3, every 3-5 days; from four months on, water according to temperature, from every 2-5 days in summer to every 14 days late fall through mid-winter.

Prune: Prune only after danger of the last frost is over in late winter or early spring. Flower buds develop during the winter dormant period, so pruning after the last frost makes it possible to avoid excess flower removal.
Citrus trees are best grown as shrubs, so that leafy branches protect their entire trunk from direct sun. Only prune the lowest branches if their tips touch the ground. If you prune up from the bottom to expose the trunk, you must paint it with a tree trunk paint to avoid sunscald.
Remove branches that are dead, damaged, diseased, or malformed. Remove any branches growing less than 45° from the vertical because they may split away as they get larger. Remove any new branches that have an angled cross section (malformed) rather than round. These have restricted veins and will not fruit well. Remove any branches growing from below the trunk graft as they occur. These are rootstock branches, not fruiting stock branches, and will produce inferior fruit.
Never prune to restrict the size of a citrus tree. Rootstocks are used to control the size of these trees.
Remove grass and other plants under the canopy that can compete for water and nutrients by hand-pulling, not with tools that can damage roots close to the surface.

Litter: Leaves throughout the year, mostly during flowering. Flower and fruit drop in spring and summer as the tree self-regulates the number of fruit it can bear.

Propagation: Seed cleaned and planted in containers soon after fruit harvest. Semi-hard leafy cuttings removed and planted late spring. Semi-hard leafy cuttings removed during warm months and grafted onto citrus rootstock.

Pests: The Giant Swallowtail Butterfly caterpillar larvae resembles bird poop and has white and black and/or brown splotches. On a large plant it will cause no harm. On a small plant, relocate it to a large citrus.
Leaf wrinkling in the summer may be due to thrips or heat. Thrips do no real damage. They are attracted to plants that are given too much nitrogen or are overwatered. If you do not see scars on the leaf, it is probably due to heat, and watering should be increased. This form of leaf wrinkling is most often found on Mandarins as opposed to other citrus. See Citrus: Diseases and Disorders

Uses: Edible fruit, ornamental, shade.

The scientific synonym of this plant is Citrus reticulata. Seedless cultivars are available.

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