Cultivation of the Mulberry Tree involves two main species, with a long tradition in our country: the white mulberry and the black mulberry. This tradition was once mainly linked to silkworm farming. Over the decades, this cultivation declined, but in recent years, efforts have been made to revive it. This is particularly true in domestic settings, as the mulberry tree is straightforward to cultivate and is also appreciated for its ornamental value and excellent productivity.
Let’s get to know this cultivar better, which in spring gives us mulberries, a sweet fruit that can be consumed fresh or used in various artisanal preparations.
Botanical classification and origins of the mulberry tree
The mulberry tree, scientifically known as Morus, belongs to the family Moraceae.
The main species present in Europe are two: the black mulberry, Morus nigra, and the white mulberry, Morus alba.
The black mulberry
The black mulberry is native to the countries bordering the eastern Mediterranean coast. It spread in Europe before the Roman era. It was known in ancient times as the “moro”, probably because it was cultivated exclusively for its fruits.
The white mulberry
The white mulberry, on the other hand, is native to China. Its history has always been linked to silk farming. Empress Si Ling Chi of China, as early as 2,700 BC, noticed some caterpillars eating the leaves of the white mulberry before spinning their cocoons. Fascinated by the sheen of the produced thread, ideal for weaving the veil of an empress, she ordered these caterpillars to be cultivated. Thus began silk farming, and with it, the cultivation of the white mulberry, the only plant capable of nourishing these demanding caterpillars with its leaves. When the secret of silk production was discovered in Europe in the 15th century, both the silkworm and the white mulberry were introduced. They spread rapidly, especially in Mediterranean countries.
Unfortunately, in the early 20th century, with the introduction of synthetic fibers, undoubtedly more economical, sericulture lost its economic relevance, and with it, the cultivation of the white mulberry experienced an inexorable decline.
Characteristics of the mulberry tree
The botanical characteristics of different varieties of the mulberry tree are quite similar. In some cases, the differences regarding the appearance of the plant and, above all, the mulberries, are minimal.
The mulberry is a deciduous plant, meaning it loses its foliage during autumn and regains it in spring.
It is a large, imposing tree that can reach considerable heights. It has a very broad and lush canopy, which over time tends to assume a globular shape.
Among the two species we are analyzing, the white mulberry tree, if left to grow without pruning, reaches the larger dimensions, both in terms of height and width.
The black mulberry tree, on the other hand, has a smaller development but is more resistant to low temperatures. For this reason, it can be cultivated at altitudes above a thousand meters without any problem.
The mulberry tree has a highly developed and expansive root system. These roots are robust and elastic, with a yellow-orange color. Due to the strength of its root system, the mulberry tree was used to control landslides.
The trunk of the mulberry tree has an upright bearing and can reach up to 70 cm in diameter. The canopy is formed by dense irregularly shaped branches.
The wood of the mulberry tree is light, especially in young specimens. It is also very flexible and easy to work with. The bark is smooth and light in young trees, while it becomes darker, with a brown-grayish color and deeply fissured with longitudinal cracks over time.
In the black mulberry tree, the leaves are large, with slightly serrated edges and short, robust stalks. They are bright green on the upper side and slightly hairy on the lower side.
In contrast, the leaves of the white mulberry tree are smaller, with smooth leaf pages.
The flowers of the mulberry tree are monoecious, meaning the male and female flowers are on the same plant. Moreover, the mulberry tree is self-fertile, so a single specimen is enough for self-pollination and fruit production.
The small flowers are grouped in inflorescences, located in the axils of the shoots of the branches of the year.
These inflorescences, greenish in color, are not very showy, open in April, and are pollinated by the action of the wind.
The most striking feature of the mulberry tree is its fruits, the mulberries.
After pollination, the inflorescence begins to swell. Each single flower then turns into a tiny drupe, which becomes succulent, changing color and consistency.
The collection of tiny drupes forms the mulberry, which is considered a false fruit, called sorosis. The actual fruit consists of the central part and the drupes covering the pulp.
The ripening period, depending on the variety, starts from June and continues throughout the month of July.
The fully ripe black mulberry is indeed black in color. It is very juicy, firm, with a flavor between sweet and tangy. It is the most cultivated species for fruit production.
White mulberries, on the other hand, have a sweet but tasteless flavor, as they have little acidity. At full maturity, they have a yellowish color and soft consistency. White mulberries must be consumed immediately and are not very resistant to handling and transportation.
Mulberry tree cultivation
The mulberry tree is a very hardy fruit tree, and its cultivation does not present particular difficulties, as we have seen for other fruit trees such as the cherry tree, lemon tree, persimmon, kiwi, or pomegranate.
Climate and soil
The mulberry tree is highly resistant to climate variability. Especially different varieties of black mulberry can withstand temperatures as low as -15 °C. Therefore, it can be cultivated from north to south without particular difficulties.
Regarding the soil, the mulberry tree can be grown almost anywhere. The plant thrives even in poor and arid soils, although more favorable conditions can increase fruit productivity.
Ideally, prefer soils with a neutral pH, with good soil preparation and a fair amount of organic matter.
Exposure and planting distance
For the exposure of the mulberry tree, it is always good to choose a sunny position. In fact, you can use its imposing canopy to provide natural shade in your garden. Be careful not to place the mulberry tree too close to sidewalks or walkways as mulberries, when they fall on the ground, can stain and leave challenging marks to clean.
As mentioned, this plant has a large development, so demarcate a circumference of at least six meters between the mulberry tree and other fruit trees.
The mulberry tree is propagated in the nursery by cuttings. For transplantation, it is advisable to purchase plants that are already grown in a soil block. Usually, plants that enter production from the third to the fourth year are commercially available. Differently, when starting from seeds, production starts very slowly.
Mulberry trees are transplanted into the ground in autumn or at the end of winter, before the arrival of warm weather.
Irrigation and fertilization
The cultivation of the mulberry tree does not require particular efforts even regarding water supply. The plant thrives well in conditions of high drought. However, in the first few years of life, during very dry periods, it would be good to intervene with some water.
Fertilization to support vegetative growth can be done in the winter season. The best method is to place some manure around the trunk, hoeing superficially.
Mulberry tree pruning
The mulberry tree is one of the plants that best withstands pruning, even drastic or incorrect pruning.
The purpose of pruning the mulberry tree is to thin out the canopy, ensuring better internal ventilation. It can be done to increase fruit production or simply for ornamental purposes.
The best time for pruning operations is the end of winter, in the months of February and March.
Pests and diseases
Regarding pests and diseases, the only problems a mulberry tree may encounter are related to scale insects or aphids. We have already discussed both these insect pests and their biological defense in previous posts.
Harvest and uses
The main problem in harvesting and using mulberries is their rapid perishability. The fruits must be harvested when fully ripe, that is, when they easily detach from the peduncle, which makes handling difficult. This applies especially to packaging and transportation, which has caused the fruit to lose commercial value and, unfortunately, consequently, agricultural interest.
On a domestic cultivation level, the perspective changes. In our opinion, the mulberry tree can undoubtedly be a fruit tree to focus on.
Mulberries are ideal for making excellent and tasty jams or fantastic ice creams. It just takes some organization not to waste these sweet fruits.
Another preservation technique, widely used in Middle Eastern countries, is the drying of black mulberries, which can thus be stored for longer.
- National Library of Medicine: “Mulberry leaves and their potential effects against cardiometabolic risks: a review of chemical compositions, biological properties and clinical efficacy”.
- Saudi Journal of Biological Sciences: “Nutritional constituents of mulberry and their potential applications in food and pharmaceuticals: A review”.