The Jujube Tree originates from China, but it also has a long tradition in other countries. Jujubes, in general, are greatly cherished, both for their unique flavor and their therapeutic properties. The fruits reach full maturity towards the end of summer, in the month of September. The cultivation of the tree was widely practiced in Italy, especially in the South, as this species prefers a warm climate and poor soil. However, over time, this cultivar has been forgotten. Today, it is cultivated almost exclusively in family orchards or found in the wild.
Let’s get to know the jujube tree better and explore its characteristics, especially how to cultivate it.
The Jujube Tree
The jujube tree, scientifically known as Ziziphus jujuba, belongs to the botanical family Rhamnaceae. This family is often found in scientific texts with synonyms such as Ziziphus zizyphus or Ziziphus sativa.
It is a plant of Asian origin, but it has been known on our continent since ancient times. The Romans introduced it to Italy during the time of Emperor Augustus, but the jujube was already known to the Greeks. Its name comes from the Greek Zizyphon.
Today, jujubes are cultivated with some intensity only in certain areas of our country, such as Tuscany, Campania, and especially in Veneto. In the area of the Euganean Hills, in a small village called Arquà Petrarca, the famous jujube broth is born and still produced today. It is a typical liqueur, sweet and flavorful, prepared using dried jujubes.
Botanical Characteristics of the Jujube Tree
Before we understand how to cultivate a jujube tree, let’s explore its botanical characteristics. The tree does not reach large dimensions, at most, when no pruning intervention is carried out, it reaches a height of 5-6 meters. It is a plant with slow growth; several years are needed to bring it into full production. The jujube has a shrub-like form, its shape is contorted, with dense and intricate branches. It is a deciduous species, meaning it loses its leaves during the winter. It is a thorny shrub; between the internodes of the branches, there are pairs of spines, of which only one will develop over the years.
The root system of the jujube tree can go very deep, allowing it to find moisture reserves in the deep layers of the soil. As a result, it can grow on dry soils and in arid climates. The young bark is grayish-light, while the old bark is furrowed with deep cracks from which a reddish bottom can be seen. The leaves are alternate, small in size, with serrated edges and a glossy appearance. The jujube tree blooms and bears fruit on the branches of the year, which carry buds grouped in a crown shape. The flowers are very small, hermaphroditic, with a calyx divided into green, triangular lobes, and with a corolla composed of 5 whitish petals. The flowering period extends from June to August. The flower is highly appreciated by bees, from which they collect pollen and nectar.
The jujube is a small oval-shaped drupe, with a pericarp that changes color from initial green to the brown of full ripeness.
The mesocarp, or flesh, is rather floury in texture and is white-yellowish in color.
Inside the fruit, there is a single pit, similar to that of an olive, which in Persian cuisine is known as “annab”. Full ripening occurs between the months of September and October. The taste of jujubes, when picked while still green on the tree, is similar to that of an unripe apple. When they reach full maturity, the taste sweetens, reminiscent of dates. The ideal time to harvest the fruit is when it is dark brown and starts to wrinkle on the branches. The ripening of the fruits is staggered, meaning not all of them ripen at once, and the harvest is done gradually. Once harvested, they can be further preserved by drying them in a dark and dry place. This way, jujubes can be stored for several months.
How to Cultivate the Jujube Tree
The jujube tree is a very hardy tree that adapts to difficult conditions where other trees struggle. Regarding pedoclimatic requirements, it prefers a warm climate and withstands periods of prolonged drought. The ideal exposure for this plant is in full sun, especially in areas with intense cold winters. However, it also tolerates temperatures as low as -15°C.
When the plant is young and abundant snowfall is expected, it is advisable to protect the vegetative parts. This prevents young branches from breaking under the weight of the snow. If your soil is highly exposed to winds, it’s recommended to choose a more sheltered location.
Soil and Fertilization
The jujube tree adapts well to poorer, calcareous, rocky soils lacking organic matter. The key is to avoid soils that are too clayey, as they can cause water stagnation, which the plant avoids. Regarding fertilization, it doesn’t have specific requirements. In the first years of cultivation, it’s good to feed the plant with a bit of organic fertilizer, such as worm humus. This can be done every two years in the autumn.
The reproduction of the jujube tree can be done either through planting seeds or rooted suckers, or through grafting.
In the first case, planting should be carried out in the autumn. Grafting, on the other hand, is done in late winter, using the “cleft grafting” technique. An alternative period could be summer, using the budding technique. Regarding planting distances, unlike other fruit trees such as almond, hazelnut, persimmon, or pomegranate, since the tree does not grow to large dimensions, shorter distances of about 3 meters between plants are sufficient. The jujube tree does not require an irrigation system or regular irrigation interventions.
Pruning the Jujube Tree
The main pruning intervention of the jujube tree should be carried out during planting. It’s necessary to shape the tree according to a chosen form, somewhat similar to pruning the olive tree. The jujube tree can be trained into different forms; the main ones are columnar, spindle, or pyramid. The training phase is lengthy, ranging from 7 to 9 years. During this period, pruning interventions should be limited to canopy containment and the removal of branches damaged by weather conditions. After the tenth year, interventions can be more significant but still more contained compared to other fruit trees.
Pests and Adversities
As emphasized several times, the jujube tree is very hardy and generally does not suffer from pest attacks. The most frequent problems can be related to incorrect cultivation techniques. The choice of a wrong soil, with the presence of excessive water stagnation, can lead to the onset of cryptogamic diseases, such as anthracnose, gray mold, rust, collar rot, and jujube cercospora. However, by addressing the root problem, avoiding stagnation (perhaps by implementing adequate water drainage measures), fungal diseases also become rare for this cultivar.
- Tradit. Med. Res: “(Ziziphus jujuba Mill.(Rhamnaceae)): A review on its pharmacological and phytochemistry” – The article provides a comprehensive review of the pharmacological properties and phytochemical constituents of jujube.
- Journal of Medicinal Plants: “Jujube, a super-fruit in traditional Chinese medicine, heading for modern pharmacological science” – This research emphasizes the importance of jujube in traditional Chinese medicine and its potential in modern pharmacological studies.
- Unique J Ayurvedic Herb: “Ziziphus (ennab) of the middle east, food and medicine” – The article discusses the nutritional and medicinal value of jujube, highlighting its significance in various cultures.
- Journal of nutrition and metabolism: “Potential Benefits of Jujube (Zizyphus Lotus L.) Bioactive Compounds for Nutrition and Health” – This paper explores the nutritional benefits and health implications of bioactive compounds found in jujube.
- The Plant Journal: “Metabolome selection determined the edible jujube acquired during domestication” – The study investigates the metabolomic changes in jujube during its domestication, emphasizing the medicinal compounds that contribute to its value.
- Economic Botany: “The jujube (Ziziphus jujuba Mill), a multipurpose plant” – This article provides insights into the various uses of jujube, from its culinary significance to its medicinal properties.
- Scientia Horticulturae: “Physico-chemical properties and antioxidant capacity of different jujube (Ziziphus jujuba Mill.) cultivars grown in loess plateau of China” – The research delves into the physicochemical properties of different jujube cultivars and their antioxidant capacities.
- Food Science and Nutrition: “Morphological and chemical characterizations of jujube (Ziziphus jujuba Mill.) to select superior accessions” – This study focuses on the morphological and chemical characterizations of jujube to identify superior varieties with enhanced medicinal properties.