Ash - Fraxinus

Hard, flexible, robust and with a fine appearance, ash is one of the best and most versatile woods. It is used for myriad purposes - including the design and crafting of custom wood furniture such as chairs, tables (for example in my Coral table), and bespoke office desks - yet it has often been referred to as ‘the poor man’s oak’. This is a misrepresentation, as it suggests ash to be of an inferior quality to oak, which it is not. Indeed, for many applications ash would be preferred by woodworkers over oak. Although it is true that ash is generally cheaper than oak, this has more to do with customers’ emotional preferences than any inferior qualities. As will be demonstrated and discussed herein, ash is in fact a better choice of wood for a great many purposes, and this has been demonstrated through centuries of widespread use.

The ash tree is a large deciduous tree with a straight bole and high, open, domed crown. Ash trees are native to temperate regions of the Northern Hemisphere and are widespread across Asia, Europe and North America. It belongs to the Fraxinus genus of the Oleaceae family. There are several species of ash trees, but the most notable distinction is between brown/black ash (Fraxinus nigra) and white ash, although this too can be broken down into European ash (Fraxinus excelsior) and Japanese ash (Fraxinus mandschurica). White ash is lighter in colour and the growth rings are wider spaced, whereas black ash has a darker colour and the growth rings are much closer together[i]. Generally European/UK ash is considered superior though, as it has a higher density and is tougher and better for steam bending [ii]. It is Fraxinus excelsior we will focus on here.

Ash grows best on deep, calcareous, moist, loamy soils but is widespread. Furthermore, not only does ash grow just about anywhere in Britain, but it can also grow very fast. In fact, ash is one of the most productive hardwoods we have, yielding more than all other hardwoods with the exception of beech[iii]. The volume of timber produced can be as much as 10m³ per hectare per year (although more typically 4-6 m³). Ash is also a pioneer species, meaning that it is quick to seed and grow in vacant ground and then grows fast for the first 40-60 years; this is a common rotation age for commercially grown ash in the modern era. Historically though, ash trees would have been felled before they reached this age. In contrast, oak takes much longer to grow and up to 150 years before it is ready to harvest[iv]. Furthermore, ash trees also mature early: a piece of wood six inches in diameter is just as valuable and durable as timber from a much larger tree. As a result, ash has historically often been coppiced.

Ash trees are also known for their tall, straight trunks.  The bark is smooth and pale brown to grey, but vertically fissures as the tree ages. Unlike many of the UK’s larger native trees, ash has a relatively short life, rarely exceeding 200 years[v], whereas oak trees may quite typically live for 600 years and are classified as ancient from 400 years onwards[vi]. Ash trees have pinnate leaves, which are arranged in 3-6 opposite pairs along the stem and fall in autumn while they are still green. The male and female flowers generally grow on different trees. Once pollinated by wind, the female flowers develop into conspicuous winged fruits [vii].

Ash grows in temperate regions in which the growing season is only part of the year – roughly March to October. In ash there is a clear contrast within a single growth ring between the inner layer of xylem ‘earlywood’ and the outer ‘latewood’. The earlywood grows quickly and results in thin-walled, lower density cells with wider vessels as compared to the latewood cells which are smaller, thick-walled, denser and darker. The vessels in ash are medium to moderately large in size. The latewood also contains a greater proportion of lignin and other wood fibres that give strength and toughness to wood. As a result of the differences between the earlywood and the latewood, ash is known as “ring-porous” (see Figure 1) as opposed to “diffuse-porous.” Ash therefore has a particularly conspicuous growth-ring figure, especially when flat-sawn (see Figure 2, for example), although it does not have the conspicuous rays that can be found in oak. Interestingly, fast grown ash with wider spaced growth rings is stronger[viii]. This is because faster grown trees have a higher proportion of late wood to early wood and therefore are denser than slower grown trees. In the mill it is possible to easily assess the speed of tree growth by counting number of growth rings per inch (>20 = slowly; <10 = fast).

Figure 1[ix] – magnified end grain of ash showing earlywood with large pores and latewood with small pores

Figure 2 – conspicuous growth-ring figure in flat sawn chair seat

Ash are relatively large, typically straight grained trees of 20-35m in height, with boles of 60cm to 1.5m in diameter[x] making a large proportion of the tree useful for producing timber, although ash also burns well and has historically been used for firewood and charcoal production. In terms of appearance, European ash is white with a temporary pale-pink tinge when first cut, whereas Japanese ash is darker in colour (pale brown) and American ash is grey-brown with a reddish tint. Logs containing irregular dark and brown or black heart are also sometimes found. These are known as ‘olive ash’ despite not being a different kind of wood and these are sold separately. Figure 3 clearly shows the difference between the normal ash and the olive ash in the centre.

Figure 3 – shows severe splitting and contrast between white ash and olive ash. This was ash that I had milled myself and formed the legs of this bespoke HiFi cabinet

Ash dries readily, although it is prone to distort if dried too rapidly. Although it is generally not known for checking/splitting, occasional severe end splits can occur. Figure 3 shows an example of this extreme splitting which occurred shortly after milling the wood. Shrinkage is medium, with values from green to 12% moisture of 4.5% radially and 7.0% tangentially[xi]. Any distorted wood does respond well to reconditioning treatment though. When heated by steam, the lignin in the wood is softened, allowing the wood to be bent. When the wood cools, the lignin resets and the new shape is retained. Ash is particularly favoured for steam bending for a number of reasons: it is generally a straight grained wood, which is very important for steam bending as defects will cause the wood to rupture; it dries readily; and it holds its bent form very well. For steam bending though, trees from well-drained soil tend to be best and in fact it is better not to kiln-dry ash because it dries too fast and too much; air dried timber is better.

Another property of ash that has lent itself to its widespread and historic usage is that it cleaves very well, both radially (through the centre of a round piece of wood) and tangentially (perpendicular to the grain but tangential to the growth rings)[xii]. This is because the direction of the grain in ash is commonly, and notably, straight. As a result, historically, people with limited access to equipment and nothing like today’s machinery have been able to split ash into manageable sized pieces for shaping into chair legs, for example. This process is something known as bodging, and involves using unseasoned wood to make chair legs and parts, something that ash is perfectly suited for due to its good elasticity.  Furthermore, ash’s exceptional steam bending properties mean that it has been used to produce bent chair parts for hundreds of years. Due to the easy cleavability of ash, pre-boring is advised when nailing to avoid splitting the wood.

In terms of its other working properties, ash is moderately stable in use; it is very tough and strong (about the same as beech and oak but 20% harder and stiffer); it saws and machines easily with only a moderate dulling effect on blades and it takes all finishes and glues well. These properties make it well-suited for a wide range of bespoke furniture design applications—from functional pieces like record player stands to sculptural, organic furniture forms. Whilst its weight can vary (F. excelsior: 580[xiii]-710 kg/m^{3 [xiv]} ; 690kg/m³ at 12% moisture content), as a general approximation it is about the same as beech. The only apparent drawback to ash is that it is perishable, meaning that it is not suitable for outdoor furniture unless it is thoroughly treated. It is also susceptible to pin-hole borer (the living tree), the powder post beetle (sapwood), and the common furniture beetle, Anobium. Ash heartwood is perishable and moderately resistant to preservative treatment but black heartwood is resistant in itself[xv].

Strong, impact resistant and not too heavy, ash does not splinter and wears smoothly, making it perfect for axe and other handles. This makes it one of the most commonly used hardwoods for tool handles—particularly in shovels and hammers where toughness and impact resistance is important[xvi]. Its properties mean it has a wide array of uses including: a variety of sports goods such as baseball bats, gymnasium equipment, cricket stumps and snooker cues; ladder-rungs; arctic sleds; bent umbrella handles; bent work in boat-building; and custom made furniture, particularly bent work in furniture. In terms of furniture, ash was often used in Georgian and Victorian furniture as it was locally sourced and there was reduced supply of oak following the ship building in the Napoleonic wars. It was particularly used as draw linings in chests of draws and wardrobes[xvii] but due to its uniformity and simplicity of figure, trunk wood was seldom used to design entire furniture fronts. That said, a good shellac polish can be seen to “fire” the wood, allowing the structure of the wood to emerge more clearly and turning the weak colour stronger and warmer[xviii].

The material properties of ash are beautifully summarised by Robert Penn who writes that, whilst frame chairs are not exclusively produced from ash, “wherever it grew well, it was the material of choice: it was cheap and available, fast-growing, readily-cleaved, easily-bent, light, strong, and elastic enough to take the bashes and crashes of daily life” [xix]. 

It is undoubtedly cheaper than oak, despite its arguably preferable characteristics. For example, Sutton timber lists 41mm waney edge ash kiln dried for £26 cft as compared to £36-50 for Oak[xx], £75 for Elm, £30 for Cherry, whilst Wentwood timber list ash for £26 cft as their second cheapest timber after alder, as compared to £35-58 for Oak[xxi].

Apart from its material properties, another thing so remarkable about ash is the widespread recognition of these properties through its specialised usage for thousands of years and across different cultures. In Homer’s epic, The Iliad, Achilles’ spear is made from ash cut from a tree from the summit of Mount Pelion and polished by the goddess Athena[xxii]. Achilles used this ash spear to kill Hector. Furthermore, both Odin and Thor were said to have magical spears made of ash, as did the riders of Rohan in The Lord of the Rings. In fact, In Norse mythology, ash was the 'Tree of Life' and the first man on Earth was said to have come from an ash tree[xxiii]. Even today it is sometimes known as the 'Venus of the woods'. These advantages have been recognised for a long time – around 1400, James I, King of Scotland, enacted a statute that required every landowner to plant and maintain ash trees in numerical proportions to their holdings.

Unfortunately, the current spread of ash dieback is expected to kill around 80% of ash trees across the UK. Ash dieback (Hymenoscyphus fraxinus) is a fungus, spread by the air, which originated in Asia and has limited impact on Fraxinus mandshurica but is devastating to Fraxinus excelsior which has not evolved with the fungus[xxiv]. The fungus grows inside the tree, eventually blocking its water transport systems, causing it to die. It was first recorded in the UK in 2012 and we are still early on in the epidemic but already the effects can be seen and felt as landowners and councils are implementing widespread felling schemes to alleviate the risk of compromised trees falling and causing injury. The fungus does not effect the timber at all if the trees are felled early on but trees which have been infected for a long period of time can become more brittle and harder to work with, which is a further incentive for stakeholders to fell trees early. There is some hope, however: a small proportion of trees appear to show some natural resilience and government funded research programs are underway to produce seedlings resistant to the fungus. Unfortunately, widespread felling programs risk harming the possibility for recovery through natural immunity of these trees.

The effects of ash dieback will be staggering, with costs running into billions of pounds. It will change the landscape forever and threaten many species which rely on ash. In the meantime, however, it is likely that there will be a short-term abundance of this fantastic and refreshingly affordable wood. As a bespoke furniture maker, I believe we should take full advantage of what may be the last readily available European ash for a century—whether for a one-off bespoke desk, a sculptural desk design, or a quietly elegant record player stand.

[i] Hasa (2021). What is the Difference Between Ash and Oak. [online] Pediaa.com. Available at: https://pediaa.com/what-is-the-difference-between-ash-and-oak/#:~:text=The%20main%20difference%20between%20ash [Accessed 14 Dec. 2022].

[ii] Risborough, P. and Harvey, R., 1972. Handbook of Hardwoods. H.M. Stationery Office.

[iii] Penn, R. (2015). The Man Who Made Things Out of Trees. Penguin UK.

[iv] Forestry England. (n.d.). Timber and the uses of wood. [online] Available at: https://www.forestryengland.uk/timber-uses-of-wood#:~:text=These%20trees%20take%20around%2040.

[v] Starr, C. (2014). Woodland management: a practical guide. Crowood Press.

[vi] ati.woodlandtrust.org.uk. (n.d.). Oak - Ancient Tree inventory. [online] Available at: https://ati.woodlandtrust.org.uk/how-to-record/species-guides/oak/#:~:text=All%20oak%20are%20classed%20as [Accessed 15 Dec. 2022].

[vii] Woodland Trust (2019). Ash. [online] Woodland Trust. Available at: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/ash/.

[viii] Penn, R. (2015). The Man Who Made Things Out of Trees. Penguin UK.

[ix] Desch, H.E. and Dinwoodie, J.M. (1980) Timber. London: Macmillan.

[x] Walker, A., 2001. The Encyclopedia of Wood. Greenwich Editions.

[xi] Desch, H.E. and Dinwoodie, J.M. (1980) Timber. London: Macmillan.

[xii] Penn, R. (2015). The Man Who Made Things Out of Trees. Penguin UK.

[xiii] Walker, A., 2001. The Encyclopedia of Wood. Greenwich Editions.

[xiv] Desch, H.E. and Dinwoodie, J.M. (1980) Timber. London: Macmillan.

[xv] Walker, A., 2001. The Encyclopedia of Wood. Greenwich Editions.

[xvi] Woodland Trust (2019). Ash. [online] Woodland Trust. Available at: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/ash/.

[xvii] Antiques World. (2013). Antique Furniture - Types of Wood. [online] Available at: https://antiquesworld.co.uk/antique-furniture-types-wood/.

[xviii] www.galerie-balbach.de. (n.d.). Antique furniture from ash. [online] Available at: https://www.galerie-balbach.de/en/worth-knowing/wood-species/ash/ [Accessed 15 Dec. 2022].

[xix] Penn, R. (2015). The Man Who Made Things Out of Trees. Penguin UK.

[xx] Sutton Timber. (n.d.). Timber Prices. [online] Available at: https://www.suttontimber.co.uk/trade/prices/.

[xxi] www.wentwoodtimbercentre.co.uk. (n.d.). Prices. [online] Available at: http://www.wentwoodtimbercentre.co.uk/Prices.htm.

[xxii] Penn, R. (2015). The Man Who Made Things Out of Trees. Penguin UK.

[xxiii] Woodland Trust (2019). Ash. [online] Woodland Trust. Available at: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/ash/.

[xxiv] Woodland Trust (n.d.). Ash Dieback (Hymenoscyphus fraxineus). [online] Woodland Trust. Available at: https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/tree-pests-and-diseases/key-tree-pests-and-diseases/ash-dieback/.‌