Description: small size, perennial evergreen trees that are grown in tropical and subtropical climates. Does not tolerate frost. Citrus fruits are normally harvested in the area situated at a latitude between 40º North and 40º South which is 'Mediterranean' climate.
Start bearing fruit 3-5 years from planting. Full production after 8 years.
Harvest: 5 - 6 months after flowering. Only small percentage of flowers produce fruit.
Soil: rich, well drained. Need periodical fertilizer, irrigation and pruning.
Harvest: citrus fruits do not ripen further after harvest. Thus it is important to pick at of maturity.
Maturity: Watch for color, juice content, soluble sugar level and acid ratio. Best harvested after 8am to allow dew to dry. If fruit is harvested wet, it will become dry and spoil easily.
Sensitivity: Citrus, especially lemon and lime are cold sensitive. Will die in frost.
General: The trees do best in a consistently sunny, humid environment with fertile soil and adequate rainfall or irrigation. Though broadleaves, they are evergreen and do not drop leaves except when stressed. The trees blossom in the spring, and fruit is set shortly afterward. Fruit begins to ripen in fall or early winter months, depending on variety, and develops increasing sweetness afterward. Some hobbyists grow dwarf citrus in containers or greenhouses in areas where it is too cold to grow it outdoors. Consistent climate, sufficient sunlight, and proper watering are crucial if the trees are to thrive and produce fruit.

Interesting facts about citrus:
For hundreds of years, sailors and explorers have eaten lime to prevent scurvy on long sea voyages.
Lime actually increase in weight after picking.
Lime turn yellow while ripening and become juicier and sweeter.
Lime are more fragrant and more acidic than lemons.

Mandarins
Mandarins are usually neat, small growing ornamental trees with prolific cropping abilities, bearing sweet, juicy fruit. Burgess scarlet – Tangerine type mandarin. Medium size, peels well. Fine textured, juicy, aromatic flesh. Vigorous grower. Ripens late (Sept-Dec).
Clementine – Very sweet, deep orange skin. Does well in cooler climates. Early fruiting (July-Sept).
Encore – Heavy cropping and easy peel. Yellow-orange skin. Juicy, sweet and aromatic. Ripens late.
Satsuma – Hardy, open tree. Mild flavour, easy peel and easily segmented. Seedless. Must be picked as soon as ripe. Early fruiting (July).
Miyagawa Wase and Satsuma Silverhill are both improved Satsuma hybrids.

Tangelo
Tangelo originate from a grapefruit/mandarin cross. A deliberate or accidental hybrids of any mandarin orange and the grapefruit or pummelo. Tangelos range from the size of a standard sweet orange to the size of a grapefruit, but are usually somewhat necked at the base. The peel is fairly loose and easily removed. The pulp is often colorful, subacid, of fine flavor and very juicy. The trees are large, more cold-tolerant than the grapefruit but not quite as hardy as the mandarin. Nucellar embryos are not uncommon in these hybrids and most of the cultivars are self-sterile, so a majority come true from seed. Tangelos are not commonly grown in California but are produced commercially and in home gardens in Florida. They are much more satisfactory on limestone in southern Florida than the sweet orange and are prized for their quality. Seminole – Large growing tree, a NZ favorite. Sweet, tangy flavour and extremely juicy.
The Tangelo is citrus fruit that is a hybrid of a mandarin orange and a pummelo or a grapefruit. It may have originated in Southeast Asia over 3,500 years ago. The fruits look like good-sized oranges and have a tangerine taste, but are very juicy, to the point of not providing much meat but producing excellent and plentiful juice.

Orange
Oranges are the most consumed citrus crop world wide, fresh or juiced. Their history has been traced back as early as 2201 BCE. Bests Seedless – A NZ variety that produces medium sized naval style fruit. Ripens mid season (Sept-Nov).
Washington Navel – Medium sized thin-skinned fruit. Ripens early summer.
Carters Navel – Offspring of Washington Navel. Ripens earlier and has a finer texture than its parent.
Harwood Late – Also known as Valencia Orange. Medium sized, well coloured, thin skinned fruit. Latest to ripen (late Nov-Dec).

Grapefruit
First recorded in the West Indies. Normally large growing trees. Grapefruit need many sunshine hours to ripen properly, so trees need to be suitably placed. Allow fruit to remain on tree until fully ripe.
Golden Special – Tolerant of cool summer and winter conditions. Major NZ commercial variety.
Wheeny – Produces good quality, medium sized, thin skinned, pale coloured fruit. Very juicy. Heavy puckering of leaves is natural, and not due to disease. Ripens Oct-Jan.
Cutlers Red – Fantastic deep red skin make this grapefruit something special. Sweet flavour, ideal as a breakfast treat.

Kumquat
Cold-hardy, small growing shrubs. Fruit is highly ornamental, and can eaten fresh or used in marmalade and preserves. Ideal for containers.

Lemons
Lemons are renowned for their remarkably tart taste. The earlier a lemon is picked the more acidic the flavour. Lemons are used most often to add flavour to drinks and cooking. Trees are usually vigorous growers with a spreading habit.
Genoa – Medium sized tree, almost thornless. Fruit ripen over an extended period, are medium sized and almost seedless.
Meyer – Hardiest of all lemons, and the smallest grower, rarely exceeding 1.5m. Stems thornless, fruit sweet and ever-bearing. Ideal in pots.
Lemonade – the dessert lemon. Fruit can be eaten straight from the tree. Very mild with a grapefruit-like flavour.
Lisbon – Large growing, heavy cropping tree. Fruiting autumn and winter. Excellent flavour.
Yen Ben – Juicy flesh, sharp flavour. Vigorous growing, heavy cropping.
Villa Franca – Heavy crops over a long summer season. Greenish-yellow flesh, tangy acidic flavour. Lumpy skin normal. Few, if any, seeds.

Lime
Tahitian Lime – Neat, small almost thornless tree. Thin skinned fruit are yellow when mature. Seedless, juicy and acidic fruit. Note that the dark green Mexican lime does not grow well in Auckland’s climate as it is very sensitive to cold.
Lime (Citrus aurantifolia) is a citrus tree with a fruit that contains a very high level of vitamin C. British sailors were issued a daily allowance of lemon or lime juice to prevent scurvy, giving them the nickname Limey.
Limes are small roundish bright green fruit with a pungent flavour. However, if they stay on the tree for a long time they turn yellow and resemble a small roundish lemon. Lime juice is used in cooking and in soft drinks, cocktails and limeade (like lemonade). Lime extracts and essential oils are frequently used in perfumes, cleansing products, and for aromatherapy.

Kaffir lime
The Kaffir lime (Citrus hystrix DC., Rutaceae) is a Southeast Asian citrus plant with very pungent leaves. The hourglass-shaped leaves are widely used in Thai cuisine. Kaffir lime leaves are also popular in the west of Cambodia, but less so in Vietnam. Malay and Indonesian (especially, Balinese; see also Indonesian bay leaf) cuisines use them sporadically with chicken and fish. The leaves can be used fresh or dried, and can be stored frozen. Although the most common product of the kaffir lime tree is its leaves (which impart a sour flavour to Thai dishes such as Tom Yum, and to Indonesian food such as Sayur Assam (literally sour vegetables), the juice and rinds of the small, dark green gnarled fruit (known as jeruk obat (literally Medicine Citrus)) are used in traditional Indonesian medicine. As for the zest, it is widely used in creole cuisine and to impart flavor to "arranged" rhums in the Réunion island and Madagascar.

Tangerine
A tangerine is an orange-colored citrus fruit. They are slightly smaller in size than oranges, but their skin peels off more easily. Their flavour is less sour and more neutral than that of an orange. It is actually a type of mandarin orange. The flavour is commonly used in bottle juice or soft drinks in North America. The number of seeds in each slice (carpel) varies greatly. In one tangerine there might be 13 seeds distributed over 11 slices.

Ugli
Unusually large fruit. Free peeling, Easy to grow, very sweet. Children love them. A tangerine-like citrus fruit having a flavor between grapefruit and mandarin orange. Peeled and eaten or added to citrus saladsand other fruit salads.