Kumquat: cultivating the Chinese mandarin

Kumquat, the vast panorama of citrus fruits includes some small-sized species that are mostly associated with ornamental plants, despite having edible and healthy fruits at least as much as those of the more well-known citrus fruits. We are talking about kumquats or cumquats, small evergreen trees with small fruits in round or oval shapes depending on the type.

The most common is the Chinese mandarin (oval kumquat) but there are several species of kumquat, which we often find grown in pots. The small fruits of this plant are eaten as they are, including the peel and are very popular with children.

It is worth studying this dwarf fruit plant, which can be grown in various contexts, including the garden on the balcony. We will discover a series of tips on how to grow Chinese mandarins. It is not particularly difficult to do this by adopting the principles of organic cultivation, valid both professionally and privately.

Variety of kumquats

At a botanical level, kumquat is part of the citrus family (rutaceous plants), alongside more famous species such as orange and lemon. It is not a variety of mandarin, although it is often referred to as Chinese mandarin. Until the early 1900s, it was considered a plant of the citrus genus (like lemon), it was indicated as citrus japonica. Subsequently, a different classification was specified, our Chinese Mandarin obtained the honor of an independent genre: Fortunella. Different varieties of kumquat are identified, or rather different species of Fortunella, let’s go-to list them.

Oval Kumquat (Fortunella margarita)

It is probably the most common of the cultivated kumquats. Its botanical name is Fortunella margarita, and it is commonly called “Chinese mandarin“. It is a species of very ancient origin, it comes from southern China, has a compact appearance and a bushy posture, with slightly thorny branches. The leaves are lanceolate and glossy, dark green on the upper side and lighter on the lower side. The flowers appear in the summer and are fragrant, single, or in some cases gathered in inflorescences. From these, once fertilized, small orange fruits develop, with smooth skin and very rich in essential oils. The flavor of the pulp is sour, the peel is sweet and the fruit is eaten whole.

Round Kumquat (Fortunella margarita)

It seems that this species comes from Japan and in fact, it is called Fortunella japonica and is also called “Japanese mandarin“. Small tree very similar to the oval Kumquat, from which it differs in the leaves, which are lighter, smaller, and with more marked veins. But above all, it is the fruits that are different, because in this case, they are round instead of oval, and of good flavor.

Hong Kong Kumquat (Fortunella hindsi)

Fortunella Hindsii is a citrus fruit of Chinese origin and has thorny twigs, oval-elliptical leaves that are dark green on the upper side and lighter green on the underside. The flowers are small and also the fruits, not exceed 1.5 cm in diameter. The peel is orange and smooth and the seeds are quite large inside. The persistence of the fruit on the plant and its limited size are parameters that make it very pleasant from an ornamental point of view, even for growing in pots.


It is a hybrid between oval Kumquat and clementine and therefore presents intermediate characters to the two species. The leaves are dark green and the flowers are white and small, emitted from spring to autumn. The fruits are slightly larger than those of the oval kumquat, and round in shape is very persistent and has a sweet and sour pulp. This is also a highly regarded plant for its ornamental value.

Kumquats are not to be confused with a type of mandarin also sometimes called “Japanese Mandarin”, or improperly “Chinese Mandarin”. It is the satsuma-Miyagawa mandarin, which instead belongs to the genus Citrus (to be exact it is called Citrus Unshiu). This is also a small plant, which produces very good greenish and sweet-sour mandarins.

Where it can be grown

The kumquat is an adaptable plant, which lends itself well to being cultivated throughout Italy, thanks to its resistance to low temperatures in winter it also lives well in the north. Obviously, before planting this citrus fruit, it is useful to check that the climate and soil are suitable for ensuring the health and productivity of the fruiting tree.

Suitable climate

The positive aspect of the Kumquat, of any species of the genus Fortunella, is its resistance to winter cold, thanks to the fact that during the ripening periods of the fruits they enter a semi-vegetative rest, during which they do not develop new shoots.

Being a citrus fruit of the Rutaceae family, it desires a mild climate, but unlike other species, it resists the cold. He also holds up well in the heat, even if temperatures exceeding 35 ° C are certainly not optimal for him either.

What kumquat fears most are particularly cold winds, so it is useful to choose a sheltered position, or in the case of an extended crop, to provide a windbreak. Care must be taken if we want to keep a Chinese mandarin plant on the balcony, as the terraces are often exposed to strong winds.

The ideal terrain

The best soil for the growth of kumquat is of medium texture, that is, of an intermediate and balanced texture, neither too tending to clayey nor sandy.

If possible, choose a fertile soil, rich in organic matter, and also well-drained, not subject to water stagnation.

How to plant kumquat

To start growing kumquats, as with most other fruit plants, it is not advisable to start from the seeds but directly from the seedling. Let’s see how and when to plant the sapling.

Choose the rootstock

Usually, when we buy a kumquat seedling in the nursery we buy the plants already grafted, generally, the rootstock used is the trifoliate orange (Citrus trifoliata), which gives it little vigor and a certain resistance to cold. So the result is a plant that is not bulky and suitable for most Italian climates.

The transplant

For kumquat it is excellent to choose a well-sunny position, the best time to plant it is spring, we can plant this citrus fruit once the risk of cold returns is over.

To place the saplings, holes of a slightly larger size than the size of the clod of the purchased plants are dug, in order to ensure a certain volume of loose earth at the roots, to prevent water stagnation. As always, it is important to keep the layers of earth separate and try, as far as possible, to put them back inside the hole in the same order, so as not to alter the biological balance of the soil.

To the first layers of earth, it is advisable to mix a basic fertilizer: good mature compost, or manure as a soil improver.

The plant must be inserted very straight into the hole, covering it at the level of the collar, then it is necessary to slightly compress the earth with the feet to make it adhere and finally irrigate.

Planting layouts

Wanting to grow kumquat outdoors, in a citrus grove or in a mixed orchard, we must take into account that its maximum height generally does not exceed 5 meters and that therefore, compared to other species that tend to stand out more, they can be adopted sixths more contained and put the plants a few meters away.

How to grow cumquat

Let’s find out together what are the various precautions to take to manage a kumquat plant. As we will find out, this citrus fruit is not difficult to grow and resists insects and diseases well.


In addition to the initial fertilization that is practiced at the time of planting, every year it is important to administer organic soil improver such as compost or manure, or floured or pelleted manure, on the projection of the canopy.

During the summer we can also intervene when we water it, taking the opportunity to dilute the macerated nettle, comfrey, horsetail, or even liquid still or blood meal in the irrigation water.

These are all products of natural origin and non-polluting, suitable for eco-friendly cultivation and allowed in organic farming.


The kumquat must be watered regularly during the spring-summer season, especially during the first years after planting.

However, there is no fixed interval for interventions: you need to irrigate when the soil appears dry, and never get to impregnate it.

In autumn winter, irrigation must be suspended.


Mulching is a practice that prevents the emergence of spontaneous grass, which exerts a competition with the plant for water and nutritional resources. The most natural means to set it up are straw, hay, withered grass, leaves, to be spread in layers of about 10 cm around the plants, in a circle with a radius of at least 50-70 cm.

Alternatively, we can use black sheets, taking into account that if they are made of plastic film, they do not allow transpiration and direct absorption of rainwater.

Diseases of the kumquat

The defense against the main pathologies of citrus fruits, and therefore also of kumquat, can be carried out by resorting first of all to prevention and then to products with low environmental impact, also allowed in organic farming.

Surely we must avoid fertilizing too much, which favors the onset of fungal diseases and aphids and irrigate the foliage. Furthermore, light but regular pruning helps to keep the foliage airy and to discourage pests such as scale insects.

The kumquat is quite rustic, but we will have to pay attention to the first symptoms of dry sore, a pathogen that sneaks into the woody vessels of the plant causing it to dry out, of anthracnose, which affects twigs, leaves, and fruits, of the bacteriosis that cause depressed spots on the twigs, from which rubber comes out.

With ongoing symptoms, we can choose to treat with a cupric product, but first, it is important to take preventive measures, possibly also sprinkle with reinforcers such as propolis or horsetail decoction.

Harmful insects

Mealybugs are among the most dangerous insects for citrus fruits, and also for kumquat, and usually lurk in dense groups on the branches. If we have only one specimen attached, or at least a few, we can solve the problem by brushing the branches with propolis oleate or cotton soaked in alcohol, otherwise, we can treat the plants by spraying them with white oil.

To prevent the presence of the red spider mite, which can also attack this plant, the plants must be watered regularly, not kept in a state of drought, favorable to this parasite.

If attacks of aphids arise, recognizable by deformed leaves and buds, crumpled and sticky of honeydew, which also attracts the Sooty mold, we can treat the plants with Marseille soap or soft potassium soap.

How to prune kumquat

At the beginning of cultivation, we can prune the young kumquat sapling to direct it towards a shape, for example, the globe or vase shape, by choosing the three main branches among the shoots inserted on the stem, or even decide to let it develop according to nature, which however it leads to a graceful shape. However, it is likely to buy plants already formed in the nursery.

In the following years, we have to prune these plants a little, especially with the aim of maintaining an orderly shape, removing dry branches, and airing the foliage. We, therefore, intervene slightly on the Chinese mandarin, pruning every year with thinning and shortening.

The best time for pruning is spring before the flowers bloom.

Grow kumquats in pots

The kumquat is a fruit plant that lends itself particularly well to cultivation in pots, thanks to its small size and its ornamental value.

Surely the pot must guarantee the roots the possibility of expanding at least a minimum and therefore must be large enough. The substrate must be well-draining and every two years or so we can re-pot it in slightly larger containers.

With the cultivation in pots, we will have to irrigate more and think every year to add compost and some other natural fertilizer, such as manure in pellets, plant macerates, borlande, rock, or algae flour, or even ground lupins, a classic fertilizer for citrus fruits.

In winter, depending on the climate of our area, it is good to mulch the surface of the earth of the pot, or better still to wrap the whole pot with non-woven fabric, in order to protect the roots from the cold.

Harvesting and use of fruits

The fruits of the kumquat begin to ripen from late November, with a gradual ripening, since the flowering is also gradual. Furthermore, as fruits are very persistent on the plant, we can harvest them without haste, as we wish to eat them. The important thing is that they have reached maturity because they could not continue to mature after being detached from the plant. A well-kept plant can produce a lot of Chinese mandarins, it is not uncommon to see heavily laden kumquats. The ornamental effect is also given by the small orange fruits, in contrast with the green foliage.

Like many citrus fruits, fruits are rich in vitamin C, iron, and magnesium and we can eat them whole, directly with the peel, which is edible and also sweet compared to the pulp. We can also turn them into candied fruit, which is particularly delicious. In this case, we will first have to immerse them in water and bicarbonate, then cook them in pieces for a few minutes and finally sweeten them. In addition, it is also possible to make a jam.

You may be interested to read the Kiwano or African horned melon blogpost/ Grow the guava plant blogpost/ Lemon plant and its cultivation blogpost/ Cultivation of the fig blogpost/ The Cedar (citron lime) blogpost/ Bergamot fruit blogpost/ Lemon cultivation in pots blogpost/ Chicken recipe with okra recipe.

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