Micocoulier de Provence : Planting, Cultivation, and Care

Description and Botany

The Celtis, commonly known as the hackberry, is a majestic tree belonging to the Cannabaceae family, like hemp (Cannabis sativa) or hops (Humulus lupulus). The genus includes 60 to 70 species of deciduous trees distributed in the warm temperate regions of the northern hemisphere. Among them, the most widespread are the European hackberry or Mediterranean hackberry (Celtis australis), the American hackberry (Celtis occidentalis), the Chinese hackberry (Celtis sinensis), and the sugarberry (Celtis laevigata). In southern France and Corsica, you will find Celtis australis, hence its other names “Mediterranean hackberry” or “Southern hackberry”, which is native to southern Europe and western Asia. It is very common in Mediterranean regions. It often grows in hedges and on hillsides, up to 900 metres in altitude, where it benefits from a favourable environment for its development.

This light-loving species, originating from southern regions, requires good sunlight to thrive fully. In France, it is mainly found in lowland and low mountain areas, where it can enjoy optimal climatic and geological conditions. It stands out for its great longevity: the Mediterranean hackberry can live up to 500 years.

In the southern regions, the Mediterranean hackberry, encouraged by abundant sunlight and mild temperatures throughout the year, is a fast-growing tree. It can reach a height of 25 metres and a spread of 15 metres, making it an imposing tree. In cooler regions, where warmth is lacking, it grows more slowly and moderately but will still form a robust and resilient tree, capable of adapting.

This tree, with its short bole and dense, spreading to rounded habit, boasts beautiful dark green deciduous foliage. The leaves are alternate, ovate, and finely dentate, measuring between 10 and 15 cm in length. They are rough to the touch and have a shiny dark green upper surface, while the underside is greyish. They resemble nettle leaves, hence its other nickname, the “nettle-leaf tree”. In autumn, the leaves turn a pale yellow before falling. The bark is greyish and smooth, marked with fine longitudinal cracks.

The flowering is inconspicuous, with greenish flowers appearing during the bud burst period. These flowers give way, in June, to small, fleshy, round fruits. These hackberries are green, then reddish-black at ripeness, in early autumn. The drupes of the Mediterranean hackberry are edible and have a sweet flavour. They persist throughout the winter on the branches and are also highly appreciated by birds, who feast on these sweet and juicy fruits.

In the past, the fruits of the Mediterranean hackberry, though small and not very fleshy, were prized for their sweet taste and used to flavour liqueurs or eaten raw. Its flexible and durable wood was used to make tool handles, furniture, and other wooden objects. Today, the Mediterranean hackberry is mainly planted as a shade or street tree, particularly in cities where it provides dense and refreshing shade. Highly tolerant of pollution, it thrives in urban heat islands where air quality may be poor.

Main species

Celtis australis

It is highly valued for its dense shade. Hardy and drought-resistant, it is loved for its beautiful foliage and adaptability!

• Période de floraison April, May
• Hauteur à maturité 20 m

See the product sheet

Planting the Southern Hackberry

Where to Plant It?

The Mediterranean Hackberry is an easy-to-grow tree. Although native to Mediterranean regions, it has shown a great adaptability to various climates and soils across France. Indeed, it has begun migrating to northern regions, where it can withstand winter temperatures as low as -20°C. This is a highly resilient tree, capable of adapting to varied growing conditions. It requires a sunny and sheltered spot, protected from cold winds. While it can tolerate cold, it dislikes prolonged frost periods. Remember, this is a sun-loving tree that thrives in hot summers. Therefore, it is recommended to plant it in a sunny and sheltered location, especially in regions north of the Loire.

It thrives in deep, fresh, and well-drained soil. It can tolerate poor or slightly alkaline soils, making it an easy-to-grow choice for many soil types. The Mediterranean Hackberry needs sufficiently deep soil to allow its roots to develop properly and withstand long summer droughts.

Stunning as a standalone specimen, it is ideal for planting in the middle of a park or large garden. It is also commonly used as a street tree to line grand avenues, providing generous shade and a pleasing aesthetic.

When to Plant a Mediterranean Hackberry?

Plant it in spring, once all risk of frost has passed, or in autumn, from September to November, to ensure deep rooting before winter.

How to Plant It?

• Choose a sunny and sheltered spot, protected from cold winds, with deep, fresh, and well-drained soil.
• Dig a planting hole two to three times larger than the tree’s root ball.
• Place a layer of drainage at the bottom of the hole (gravel, clay pebbles) if your soil is heavy and poorly drained.
• Position the root ball in the hole, ensuring the collar (the base of the trunk) is level with the soil.
• Install a stake.
• Backfill with the excavated garden soil mixed with compost.
• Water generously, then regularly to encourage establishment.
• Mulch the soil around the trunk to retain moisture and suppress weeds.

Maintenance, Pruning and Care

The Celtis australis requires little maintenance. It is recommended to keep the soil moist during the first two summers after planting to promote healthy growth. After that, it will thrive on rainwater alone and won’t need additional watering. Using mulch can also help maintain good soil moisture. Once established, this tree is relatively drought-resistant.

Pruning the Mediterranean hackberry isn’t strictly necessary. However, formative pruning can be carried out on young plants to shape the framework and clear the trunk. After that, pruning every three years, between October and December, is recommended to maintain its harmonious shape and remove dead or damaged branches. This tree tolerates pruning well. Remove the numerous suckers that appear at the base of the trunk.

The Mediterranean hackberry is rarely affected by diseases or parasites.

Multiplication

The Hackberry can be propagated by sowing, a simple method to obtain new young plants.

If you have a specimen in your garden, harvest the seeds present in autumn. The seeds should be sown after cold stratification.

• Sow the seeds in autumn or spring under a cold frame or in a nursery and cover them with about 1 cm of compost
• Keep moist until germination, which can take over a year
• Transplant into open ground in spring when the seedlings are at least 50 cm tall

Associations in the Garden

The Hackberry is a majestic tree which, if left to grow freely, boasts a beautiful stature. It is therefore best suited to parks and very large gardens where it can be planted as a standalone specimen as a remarkable feature or in rows to frame a grand avenue. An exceptional shade tree, it is ideal for creating a sheltered area to rest or dine away from the sun’s intensity. You can pair it with a backdrop of evergreen bushes or conifers such as cypresses, yews, or junipers, and combine it with Mediterranean perennials, bushes, and southern trees (Lychnis, Salvia, Rockroses, Ceanothus, Teucrium, Phlomis, and Arbustus unedo).

Acer monspessulanum, Celtis australis (photo: Claudio Gioseffi), Ceanothus thyrsiflorus ‘Repens’ (photo: A. Barra), Phlomis fruticosa, Cistus albidus, and Arbutus andrachne

In the shade of this grand tree, place an Photinia serratifolia with ornamental evergreen foliage year-round. Nearby, in a large park, other trees of character can join without overshadowing it: holm oak, sycamore maple, Montpellier maple.