The ash tree is the common name for several species of the genus Fraxinus, belonging to the botanical family Oleaceae. In Europe, and particularly in Italy, the most widespread species are Fraxinus excelsior (European ash), Fraxinus ornus (manna ash) and Fraxinus angustifolia (narrow-leaved ash). These are long-lived, deciduous trees that can reach from about 10 up to 30 meters in height, depending on the species and growing conditions. 

Botanical description
Ash trees typically show:

• A broad, light, airy crown, with flexible, well-spaced branches.

• Opposite, compound leaves, made up of several lanceolate leaflets with smooth or slightly toothed margins.

• Small, inconspicuous flowers, usually without petals, grouped in panicles that appear in spring, often before the leaves.

• Fruits called samaras, elongated winged achenes that are easily carried by the wind and help seed dispersal.

The trunk is generally straight, with smooth grey bark in younger trees that becomes fissured and more deeply furrowed with age. Ash wood is well known for being elastic, tough and relatively easy to work, which is why it has long been valued in carpentry.

Food-related and traditional uses
Although ash is not a common “food ingredient” in the strict sense, some parts of the tree have specific uses:

• The manna ash (Fraxinus ornus) produces manna, a sweet exudate that flows naturally or after incision of the trunk. Traditionally dried and collected as flakes or stalactite-like pieces, it has been used as a natural sweetener, in herbal teas and in traditional herbal preparations.

• The leaves of some species, when dried, can be used to prepare herbal infusions with a slightly bitter, herbaceous taste.

• In the past, young shoots and tender leaves were sometimes eaten in small amounts in rural areas, for example boiled or added to simple soups.

• In some traditional drinks, leaves or bark were fermented or macerated, although such uses are now quite rare.

Other uses and cultural relevance
Ash has a strong presence in European tradition:

• The wood, being elastic and shock-resistant, is widely used for tool handles, furniture, sporting goods (such as handles for bats and other equipment), parts of musical instruments and floorings.

• In traditional herbalism, bark and leaves have been used in various folk remedies and herbal teas.

• In several European mythologies the ash tree is a symbolic species of great importance; in Norse mythology, for example, an ash (Yggdrasill) represents the world tree, the axis of the universe.

Overall, ash is one of the most characteristic tree species of European woodlands, appreciated both for the elegance of its appearance and for the many traditional and craft uses that have linked it to rural life for centuries.

Botanical classification

• Common name: ash tree, common ash

• Botanical name: Fraxinus excelsior

• Botanical family: Oleaceae

• Native range: Europe and the Caucasus

• Habit: deciduous tree with a wide, light crown

• Height: 20–35 m (up to 40 m in optimal conditions)

• Lifespan: perennial, long-lived

Cultivation and growth conditions

Climate

• Prefers temperate and humid climates.

• Tolerates cold winters very well.

• Not well suited to very hot, arid climates.

Exposure

• Grows well in full sun or light partial shade.

• Prefers bright sites to develop a well-balanced crown.

Soil

• Thrives in soils that are:

  • deep,

  • fresh and moist,

  • rich in organic matter,

  • well drained.

• Tolerates calcareous soils.

• Does not like very compact soils or those prone to waterlogging.

Irrigation

• Once established in open ground, usually needs little additional watering.

• In the first years after planting:

  • water regularly during dry periods.

• Mature trees tolerate moderate summer drought, but grow best with soil that stays slightly moist.

Temperature

• Very hardy, withstands temperatures well below freezing.

• Can suffer from prolonged summer drought stress in very hot regions.

Fertilization

• Does not require heavy fertilization.

• A yearly application of:

  • compost or other organic matter around the base,

  • and, in poor soils, a balanced slow-release fertilizer,
    can support healthy growth.

Crop care

• Perform light formative pruning in the early years to create a strong framework.

• Later on, pruning is limited to:

  • removing dead, damaged or crossing branches,

  • slightly thinning the crown if it becomes too dense.

• Monitor for fungal diseases and insects (leaf miners, aphids, etc.).

• Pay attention to root and trunk rots in very wet, poorly drained soils.

Harvest

• Leaves and bark are traditionally harvested in spring or early summer for herbal use.

• Seeds ripen in autumn, grouped in the characteristic hanging samaras.

Propagation

• By seed:

  • seeds need a cold stratification period (2–3 months) to improve germination;

  • sow in autumn or spring.

• By cuttings: possible but often has a low success rate.

• By suckers: in some cases the tree produces basal shoots that can be separated and replanted.

Studies

Mainly used for furniture construction it has some interesting health properties found in clinical studies: 

• the aqueous extract has shown hypotensive and diuretic actions (1)
• the seed and fruit extract may be useful in metabolic disorders related to impaired glucose tolerance, obesity, insulin resistance and inflammatory status, particularly in the elderly (2)
• the seed extract has the ability to regulate blood glucose and insulinemia, demonstrating anti-obesity effects (3)

Overall, Fraxinus excelsior contains a wide range of chemical components including coumarins, secoiridoids, phenylethanoids, flavonoids and lignans with anti-inflammatory, immunomodulatory, antimicrobial, antioxidant, photodynamic damage prevention, liver protection, diuretic and anti-allergic activities (4). 

In cosmetics, Ash bark extract is used, which is credited with skin regenerating properties due to its antioxidant characteristics.

In the last two decades, ash trees have been dying out almost everywhere in their natural habitat and particularly in Europe due to the fungus Hymenoscyphus fraxineus, transmitted by wind-borne spores, which can, however, be combated by various methods including fungal endophytes or pre-priming of defence responses.

References______________________________________________________________________

(1) Eddouks M, Maghrani M, Zeggwagh NA, Haloui M, Michel JB. Fraxinus excelsior L. evokes a hypotensive action in normal and spontaneously hypertensive rats. J Ethnopharmacol. 2005 May 13;99(1):49-54. doi: 10.1016/j.jep.2005.01.050. 

(2) Zulet MA, Navas-Carretero S, Lara y Sánchez D, Abete I, Flanagan J, Issaly N, Fança-Berthon P, Bily A, Roller M, Martinez JA. A Fraxinus excelsior L. seeds/fruits extract benefits glucose homeostasis and adiposity related markers in elderly overweight/obese subjects: a longitudinal, randomized, crossover, double-blind, placebo-controlled nutritional intervention study. Phytomedicine. 2014 Sep 15;21(10):1162-9. doi: 10.1016/j.phymed.2014.04.027.

(3) Ibarra A, Bai N, He K, Bily A, Cases J, Roller M, Sang S. Fraxinus excelsior seed extract FraxiPure™ limits weight gains and hyperglycemia in high-fat diet-induced obese mice. Phytomedicine. 2011 Apr 15;18(6):479-85. doi: 10.1016/j.phymed.2010.09.010. 

(4) Kostova I, Iossifova T. Chemical components of Fraxinus species. Fitoterapia. 2007 Feb;78(2):85-106. doi: 10.1016/j.fitote.2006.08.002.