Calamondin: The Miniature Orange

Background

Calamondin, a native citrus plant in the Philippines and China, is cultivated in Southeast Asia and elsewhere as an important crop.

In the U.S. and Europe, it is grown mainly as an outstanding ornamental. The tree, which is often trained as a bonsai, will bloom year-round; filling the air with the aroma of citrus blossom. Flower and fruit often will appear at the same time. The tree has upright branches with very few thorns and can grow up to 10 feet high. Its 3-inch evergreen leaves are broadly oval and pale green below like those of the kumquat. Its flowers are white and small. The 1 3/4 inch-wide fruit is small, depressed, globose and deep orange-yellow when ripe, loose-skinned and, segmented. The pulp is very acidic. Mature fruit can be produced year round.

It is said that it is an acid citrus, a group that includes lemons and limes. The flesh is orange, juicy and acid, with a fine lime-orange flavor. Because of this, it is usually grouped with the limes. The small seeds are few, with characteristic green cotyledons. One bite of this fruit can pucker your mouth. The fruit, when ripe, is very sour when first tasted. Subsequent tasted fruits make your mouth sweet. If the fruit is picked too soon, it is bitter.

Origin

In many Latin countries, the calamondin plant is found in backyards, and the fruit is called ‘agri-dulce’ (sweet and sour). It is known by the botanical name of Citrus mitis Blanco, Citrofortunella mitis, or Citrofortunella microcarpa Bunge and is considered a good remedy for the ‘grippe’ (cold).

Horticulturists believe that the Calamondin is a hybrid of lime and mandarin, or lime and kumquat, or kumquat and mandarin. Technically, Chinese experts say the calamansi is a hybrid between Citrus reticulata and Citrus japonica. Hybrids between Citrus subspecies have been cultivated for so long that their origins are already vague. It is widely held that most species in cultivation are ancient apomictic hybrids and selected cultivars of these hybrids – including crosses with other genera such as Fortunella and Poncirus. The early name of the fruit was given the botanical name of Citrus madurensis Loureiro by a man named Loureiro who found this unusual fruit on the island of Madura, near Java. Later it was changed to the new classification.

A man named Lathrop introduced this unusual fruit, the calamondin, in Florida in 1899 with a name ‘acid orange.’ Later, Dr. David Fairchild, who came from Panama, introduced it as ‘Panama orange.’ The fruit had come to Chile as a stock for mandarin oranges and from Chile went to Panama.

Among alternate common names are: calamondine, calamondin orange; Panama orange; golden lime; scarlet lime. Malayan names are limau kasturi (“musk lime”) and limau chuit. The Polish name is kalamondyna. In Thailand, it is ma-nao-wan; while in Japan, they call it, shikikitsu or tokinkan and in China, szu kai kat. In the Philippines, the correct Tagalog word is kalamansi. Sometimes it is referred to as calamansi, kalamunding, or agridulce. I should know I’m a Filipino.

The kalamansi is also found in many backyards of Sri Lanka. However, they prefer to use lime in their dishes. In Vietnam, the calamansi is a symbol of prosperity and it is sometimes given as a gift of good wishes on important or festive occasions.

The tangerine tree (Citrus tangerina) which looks the same is often mistaken for this plant.

Food Uses

Calamondin halves or quarters may be served with iced tea, seafood and meats, to be squeezed for the acid juice. They were commonly so used in Florida before limes became plentiful. Some people boil the sliced fruits with cranberries to make a tart sauce. Calamondins are also preserved whole in sugar syrup, or made into sweet pickles, or marmalade. A superior marmalade is made by using equal quantities of calamondins and kumquats.

In Hawaii, calamondin-papaya marmalade is popular. In Malaya, the calamondin is an ingredient in chutney. Whole fruits, fried in coconut oil with various seasonings, are eaten with curry. The preserved peel is added as flavoring to other fruits stewed or preserved.

In the Philippines, the calamondin is squeezed for its juice and added to pansit, arroz caldo, goto, over charcoal-grilled fish, pork or beef, and is an important ingredient in many dipping sauces. When used as a condiment, the juice is often mixed with fish sauce or soy sauce for that indescribable sour-salty taste.

Also, it is not toxic to dogs as widely believed since Filipino dog owners tend to include every leftover including the calamondin dipping sauce when they feed their pet dog. Let’s be clear about this. Maybe it’s the kalamansi seed that is toxic.

I think it’s the culprit because Internet sources also say that apples are toxic to dogs, however, I feed my Shih Tzu apples every day. She loves to beg for them and eat them whenever I’m eating them. I don’t feed her the apple seeds, of course. However, I do know when Shih Tzus indigest pepper and tomato seeds, they have an upset stomach and vomit.

In the tropical forests of Costa Rica, monkeys eat the fruit as well as use it as an insecticide – rubbing it all over each other.

The juice is primarily valued for making acid beverages. It is often employed like lime or lemon juice to make gelatin salads or desserts, custard pie or chiffon pie. The extracted juice, with the addition of gum tragacanth as an emulsifier, is pasteurized and bottled commercially. This product must be stored at low temperature to keep well. Pectin is recovered from the peel as a by-product of juice production. calamondin in a pot Food Value Per 100 g of Edible Portion* Whole Fruit % Juice % Calories/lb 173 (380/kg) Moisture 87.08-87.12 89.66 Protein 0.86 0.01 Fat 2.41 0.53 Carbohydrates 3.27 Ash 0.54-0.64 0.62 Calcium 0.14 Phosphorus 0.07 Iron 0.003 Citric Acid 2.81 5.52

*The chemistry of the calamondin has received only moderate attention. Wester (1924) and Marañon (1935) reported the above constituents from Philippine analyses. Mustard found the ascorbic acid content of the whole fruit to be, 88.4-111.3 mg/100 g; of the juice, 30-31.5 mg; and of the peel, 130-173.9 mg.

NOTE: Calamondins versus Kumquats

Kumquats are not calamondins – kumquats only have four segments in their internal structure and they have a thicker peel, while Calamondins are more like miniature oranges, and have seeds inside.

Other Uses

Calamondin is widely grown as an ornamental bush in California and Florida. It is grown sometimes as a house plant, and it is quite showy when fruits are ripe. The trees bloom all year under warm weather and it can have flowers, green fruits, and mature fruits at any given time. It can be grown as a dooryard tree throughout the citrus belt and will do very well as a container plant in colder locations in north Florida if protected from cold. It can also be used as a living Christmas tree.

The fruit juice is used in the Philippines to bleach ink stains from fabrics. It also serves as a body deodorant or skin and hair bleach. Some even use the fruit for dandruff treatment.

Calamondin peels effectively wash away the lingering smell of seafood after picking on them with the hands. One can also dip them into dishwashing solutions to produce a lemony fragrance.

Medicinal Uses: The fruits may be crushed with the saponaceous bark of Entada Phaseoloides Merr. for shampooing the hair, or the fruit juice applied to the scalp after shampooing. It eliminates itching and promotes hair growth. Rubbing calamondin juice on insect bites banishes the itching and irritation. It bleaches freckles and helps to clear up acne vulgaris and pruritus vulvae. It is taken orally as a cough remedy and antiphlogistic. Slightly diluted and drunk warm, it serves as a laxative. Combined with pepper, it is prescribed in Malaya to expel phlegm. The distilled oil of the leaves serves as a carminative with more potency than peppermint oil. The volatile oil content of the leaves is 0.90% to 1.06%.

Climate

The calamondin is hardier to cold than any other true citrus specie and only the trifoliate orange and the kumquat are more tolerant to low temperatures. It can be successfully grown outside throughout California, Florida, and the gulf coast. It is moderately drought-tolerant. It makes an excellent container plant in colder areas. Waterlogged areas are not suitable for cultivation because these plants cannot tolerate too much moisture.

Soil

The tree seems able to tolerate a wide range of soils from clay-loam in the Philippines to limestone or sand in Florida. They prefer well-drained soils that are kept moist and in full sun.

Propagation

Calamondin trees may be easily grown from seeds, which are polyembryonic with 3 to 5 embryos each.

For commercial fruit production in the Philippines, the trees are budded onto calamondin seedlings. In Florida, propagation by cuttings rooted under constant mist is the more common commercial procedure for pot culture. Even leaf-cuttings will root readily. Cuttings of new growth are dipped in rooting hormone and placed in a perlite-peat moss mixture and kept evenly moist (not wet) in direct light.

Plants grown from cuttings fruit during the rooting period and will reach 18 to 24 in (45-60 cm) in height in 10 1/2 months. The flowers are self-fertile and require no cross-pollination. The calamondin should root in 1 to 2 months and will grow at the rate of 1 foot (30 cm) per year. It will produce an abundant crop of fruit at the age of 2 years and will continue to bear the year around.

To produce year-round fruits, you need to stress the plants by watering them during the dry season. Combination of mineral and organic fertilizer will make the plants healthy. Mixed fertilization of ammonium sulfate and compost thrice a year will make it more healthy. Try vermitea, humus, or compost tea as fertilizer. Also, the fruit thinning technique will make the calamansi fruits bigger.

Care and Potting

Most varieties can be grown in containers, such as pots or tubs (the most popular container is a two-inch pot), with a fair degree of success.

Drainage of container is utmost importance since citrus plants can develop root problems if the drainage is not adequate. Citrus can be grown in a mixture of equal parts of peat, perlite, and a good garden loam. A mixture of peat and perlite alone is not recommended because plants tend to blow over and develop nutritional deficiencies when this mixture is used. When transplanting, do not disturb the soil or roots. Place the plant into the new pot or container that has been partially filled with soil or rooting media. Or you may dig a hole, at least 40 cm wide and 40 cm deep. Set the seedling into the hole and put back the dug soil mixed with compost.

The usual distance for planting calamondin is five meters between plants in a square, rectangular or triangular system. In a one-hectare orchard, the population density would equal to about 278-719 trees – depending on the plant spacing and the planting system to be implemented. Using a 5 x 5 meter square system spacing, the density per hectare will be about 400.

Citrus plants are not well adapted to the house environment. They grow best outdoors in direct sunlight or half shade. Indoors, they should be placed in a very well lit area. During the warm months, they should be placed outdoors. A temperature range of 70 º F to 90 ºF is adequate. Citrus trees do not grow well at temperatures below 55 ºF. Water plants as needed only, excess or lack of water will kill a tree. Allow the surface inch of soil to become dry before watering.

To produce large, delicious fruits, it is recommended to fertilize the plants regularly. Put 50g to 100g ammonium sulfate or urea, around each tree one month after planting. Do this every four months but on the second year, increase the amount of fertilizer to 200g or 300g. Use the same kind of fertilizer per tree every four months thereafter.

The tree will bear fruit on the fourth year, it is recommended that you apply complete fertilizer, like ammophos and potash, to increase fruit yield at the rate of 500g per tree. At eight to 10 years old, apply more fertilizers to the trees, from two to three kilos per tree, three times a year. First, before the flowering stage; next, two months after flowering, and last, after harvesting.

In orchard plantings, Philippine workers have established that a complete commercial fertilizer with a 1:1 nitrogen to potassium ratio gives the best growth. There are 2 applications: one prior to the onset of the rainy season and the second just before the cessation of rains. Adequate moisture is the principal factor in yield, size and quality of the fruit. Drought and dehydrating winds often lead to mesophyll collapse.

To properly apply the fertilizer, mix it with the soil. It is also good to cover the soil around each tree with dry leaves to conserve moisture. Do some weeding from time to time. Dusty leaves usually result in mite and scale infections, water the leaves with a sponge frequently to avoid these problems which may cause serious problems in small trees.

Harvesting

Calamondin trees will start to bear fruit one or two years after planting. They are harvested by clipping the stems as they become fully colored throughout the year. In the Philippines the peak season is mid-August through October. To harvest, pick the fruits from the branch, either by hand or by using a pair of scissors. Take extra care to prevent damage to the branches or to the leaves. To keep the fruit fresh, leave a portion of the stem attached to the fruit and avoid injury to the skin when harvesting.

Storage

The fruits will keep in good condition for 2 weeks at 48º to 50º F (8.89º-10º C) and 90% relative humidity. Weight loss will be only 6.5%. Waxing retards ascorbic acid loss for 2 weeks in storage but not thereafter. Potted plants for shipment can be stored in the dark for 2 weeks at 53.6º F (12º C) without loss of leaves or fruits in storage or in subsequent transit and marketing.

Pests and Diseases

The calamondin is a prime host of the Mediterranean and Caribbean fruit flies, and for this reason is much less planted in Florida than formerly. It may be attacked by other pests and diseases that affect the lemon and lime including the viruses: crinkly leaf, exocortis, psorosis, xyloporosis and tristeza, but it is immune to canker and scab. They are susceptible to chlorosis, provoked by lack of calcium and magnesium.

To keep the trees healthy and allow them to attain maximum yield, it is always best to protect them from pests and diseases. Pests are easy to spot. Zigzag marks, savoyed cuts, and rugged edges on the bark indicate that the tree is infested with citrus bark borers. These are light brown or bluish-black beetles that lay their eggs in the cuts and cavities of the calamondin bark. When the eggs hatch, the larvae feed on the bark and leaves.

To control the citrus bark borers, spray the trees with pesticides recommended for citrus trees. To prevent the pest from spreading, cut off the infected parts and burn them. Another harmful insect pest is the aphid. This greenish or brownish insect not only retards the plant’s growth, but also acts as a disease carrier. To control, spray the trees with pesticides recommended for aphids but if the pests have already attacked, cut off the infected parts of the plants and burn them.

A serious disease is citrus greening or leaf mottling. The disease is transmitted by the Asian citrus psyllid (Diaphorina citri). The psyllids live and multiply on new shoots and need to be exterminated to prevent citrus greening. Calamondin growers should implement quarantine measures immediately to prevent the introduction of diseased or psyllid-infested citrus plants – most specially, the orange jessamine or kamuning (Murraya paniculata), being a favored host of the psyllid.

Other harmful pests of the calamondin are spider mites, foliar mealy bugs, Purple Scale, and Glover’s Scale. These pests suck the tree’s sap until its leaves and fruits wither and fall, and the tree finally dies.

Aside from pests, the calamondin is also prone to diseases, such as gummosis, citrus canker, and citrus scab.

Gummosis is caused by either a lack of, or an excess of fertilizer, or damage from insect pests or machinery. The disease is marked by a dark sticky substance or gum oozing out of the infected leaves, branches, and trunk. As the disease worsens, gum secretion increases. It is recommended that as soon as this gum-like substance is noticed, spray the trees with chemicals especially recommended for gummosis control. Apply the chemical directly to the diseased bark. Some folks treat the sticky residue with horticultural oil which is found in most garden centers.

Citrus canker, a disease caused by bacteria, is characterized by raised lesions and glazed margins, with an oily appearance. Citrus canker affects the leaves, twigs, branches and the fruits. To control the canker, spray the trees with fungicide solutions when the trees area at dormant stage. Consult the dealers of fungicides for proper application of the chemicals.

Citrus scab is a disease caused by a fungus. It starts as a small pale-orange, somewhat circular, elevated spot on the leaf. A severely infected leaf becomes so distorted, crinkled and stunted that whatever remains has very little semblance to a normal leaf. To control this disease, spray with a copper fungicide solution. Following the manufacturer’s recommended application or formula. Spray when new flushes of growth have developed, or during blooming stage when two-thirds of the petals have fallen and, also two weeks thereafter until the fruits are half mature.

Questions and Answers

A popular belief in the US is that Calamondin came from China or Panama and that it is a hybrid of Kumquat and Mandarin (Clementine?). How come Calamondin still show no changes from seed. and do not exhibit Kumquat and Mandarin characteristics after several generations. I have a few dozen trees in Fl. My guests are amazed how big they get. I simply tell them I let them grow. The best time is when the green and yellow are midway. I get 45-48% juice by weight. In Central Fl we have two harvests July and November. In S Fl around Miami area, They bear fruit all year round just like in the old country.

It must be because cross breeds between Calamondin and another citrus never became popular to be widespread.

The leaves are yellowish than green, the branches are turning yellowish and don’t develop leaves.

Buy nitrogen potassium and phosphorus fertilizer or if you have an aquarium, use the old water to water the plants.