Tree to 35–40 m tall, 1.5–2.5 m dbh. Trunk monopodial, terete, or densely branched or forked with multiple codominant trunks. Primary branches massive, initially ascending, eventually spreading horizontally or nearly so, secondary branches later in horizontal planes. Crown conical in young trees, later pyramidal (or in isolated trees spreading horizontally and becoming flat topped). Bark of young trees grey, smooth, soon cracking into small plates with cinnamon-brown new growth in fissures, on old trees rough, with deep longitudinal fissures, dark grey-brown to blackish-brown, detaching in thick plates. Branchelts of two types: short (older growth) and long (young extension growth): short shoots stout, densely pubescent, with typically shorter needles borne in clusters, grey; long shoots slender, shallowly grooved, with scattered, long needles, green-yellow maturing to yellow-grey. Needles on long shoots spirally arranged, solitary close to the base of long shoots, but densely crowded obscuring the long shoots near their tips; on short shoots arranged in false whorls, of 20–45 per whorl, (1–)1.5–3 cm x 1–1.5 mm, typically short, thick, pruinose-green or silvery-grey, narrowly linear, straight or curved, rhomboid in cross-section, apex acute with a yellowish translucent spine 0.3–0.5 mm long, stomata on all sides but concentrated on two adjacent sides. Pollen cones terminal on short shoots, initially erect, subtended by needles, soon falling after releasing pollen in early autumn, sulphurous-yellow maturing to pale brown before falling. Female cones developing terminally on short shoots, maturing when these shoots become woody in their second or third year. Erect, more or less sessile, (3–)5–7(-8) x 3–5 cm, ovoid or barrel shaped, maturing to pale green with purplish edges to the seed scales, ripening to light purplish-brown. Rachis persistent, narrowly conical, pinkish grey-brown. (Farjon 1990; Debreczy & Rácz 2011).
Distribution Algeria The Tell Atlas and Aurès mountains. Morocco The High and Middle Atlas and Rif mountains.
Habitat In pure or mixed forests between 1000 m and 2000 m asl.
USDA Hardiness Zone 7-9
RHS Hardiness Rating H5
Conservation status Endangered (EN)
Taxonomic note As noted by Farjon, ‘the taxonomic distinction between C. atlantica and C. libani is at best inconsistent and…probably non existent’ (Farjon 2017). Nevertheless, he continues to treat both at species level based on their disjunct distributions, a view that horticulture surely welcomes, the difficulties regarding identification of cultivated trees notwithstanding.
Atlas Cedar is native to the mountains of northwest Africa, in the Atlas and Rif mountains of Morocco and in the Tell Atlas and Aurès mountains of Algeria. It was once widespread in appropriate habitats in these mountains but suffered declines of up to 75% throughout its range during the mid-20th century alone. As with the closely related Cedar of Lebanon, these sobering losses continue to be exacerbated by the complex effects of climate change, especially as these areas become increasingly arid, and by the emergence of new pests and diseases (Thomas 2019).
Some of the largest remaining stands include those close to the town of Azrou in the Moroccan Middle Atlas. Although illegal exploitation continues unabated there are some modest reserves in this area. Unfortunately, outside protected areas intense grazing means so many curious and attractive associates are absent, such as the Pineapple Broom Argyrocytisus battandieri, and there are few young Cedars waiting to replace the old trees. This has, however, created a remarkable woodland effect in some stands, with towering mostly single-stemmed Atlas Cedars better resembling an en masse planting than a natural forest, with a clear forest floor exaggerating their size and arguably enhancing their beauty – albeit at a considerable ecological cost (pers. obs. 2015).
Finer forests may be found in the Rif mountains in the north of Morocco. Here Atlas Cedar occurs as a minor component of forests dominated by the Moroccan fir, Abies pinsapo var. marocana, and together with Quercus faginea, Q. rotundifolia, Crataegus laciniata and a variety of shrubs, the forests are, for now, more intact than their Atlantic counterparts (pers. obs. 2015). It was from the Rif mountains that the Royal Botanic Garden Edinburgh’s International Conifer Conservation Programme (ICCP) introduced significant conservation collections in 2015. This material, possibly the first Atlas Cedar of Rif provenance to be introduced to the United Kingdom, will shortly be distributed to a series of collaborating organisations as part of ICCP’s ex-situ conservation work under numbers assigned to the collector code CAGM.
The Atlas Cedar is frequently said to have been introduced to cultivation in c. 1840 (for example Hillier & Coombes 2002) but there are contradictory references in literature, and it has even been suggested that it was introduced to France as late as 1862 (Courbet et al. 2012). It would certainly be remarkable if it had been introduced to the United Kingdom from French North Africa before it had been introduced to France, although this would follow the well-established tradition of one-upmanship and sheer devilment that characterised relations between the two countries at the time. Jacobson offers a curious if unsupported detail and reports it was ‘Introduced in 1839 when French gardener and dendrologist A. Sénéclauze received cones’ (Jacobson 1996), which is a date that is also cited by Krüssmann (Krüssmann 1985) and one which, if we are to subscribe to conventional wisdom, seems plausible.
Whatever the exact date it was certainly considerably later than the Cedar of Lebanon, which was well-established in cultivation by the 1840s. An interesting piece of history recorded by Elwes and Henry is that while Atlas Cedar was almost certainly introduced from populations in Algeria, it was ‘discovered’ in Morocco when ‘Philip Barker Webb visited Tangiers and Tetuan in the spring of 1827, and received…branches of a cedar which had been collected in the impenetrable mountains of the province of El Rif’ (Elwes & Henry 1906).
The circumstances of Atlas Cedar’s introduction to British and Irish cultivation remain uncertain. Elwes and Henry suggest it must have reached Britain during or after 1844, though they do not fully discount the possibility it may have been a little earlier (Elwes & Henry 1906). Alan Mitchell (1996) suggests with certainty that it was 1841 but gives no reference. Both works recount that Lord Somers of Eastnor Castle, Herefordshire, made his own introduction after visiting Téniet-el-Hâad in Algeria in 1845 and that his introduction yielded a glaucous form nowadays treated as C. atlantica Glauca Group. This is the earliest date for which there is irrefutable proof.
Téniet-el-Hâad was, at the time of Elwes’s visit in January 1907, ‘about a day’s journey from Algiers’ by train and then by cart, and apparently was a popular destination for the English upper classes through much of the 19th and early 20th centuries – his account goes on to mention a seed introduction made from there by Earl Brownlow in 1862 which, like Lord Somers’s introduction, yielded strongly glaucous forms (Elwes & Henry 1906–1913).
Eastnor Castle is still home to some of the finest, if not necessarily the largest, examples of Atlas Cedar that may be seen anywhere in the United Kingdom or Ireland. The ‘original’ glaucous tree introduced by Lord Somers in 1845 still grows there, as do a great many others throughout the arboretum, several of which probably originate from the same introduction. Their positions, often in groups on a slope, or well-spaced along the main drive, and regularly framing or providing the culmination of long internal views, all serve to accentuate their grandeur and beauty to great effect.
Besides the grounds of stately homes Atlas Cedars now grace just about every variety of ornamental landscape that exists in the United Kingdom and Ireland, including municipal parks, cemetaries, urban and suburban gardens (often in hopelessly restricted spaces) and, rarely, as street trees. That they have remained in vogue for so long is likely due to the enormous popularity of the glaucous forms (C. atlantica ‘Glauca’, Glauca Group, etc.) and it is interesting to note that the tallest Atlas Cedars on record in the United Kingdom and Ireland all belong to the Glauca Group. According to The Tree Register the tallest ‘ordinary’ C. atlantica is a tree in a private garden near Crieff, Perthshire, which was 35.5 m tall (1.1 m dbh) in 2017, however there are seven records representing ‘Glauca Group’ trees equalling or exceeding this. The tallest of these is a 41.5 m tree at Powerscourt, County Wicklow, Ireland, although the record for another tree of 40 m (the next tallest in the list) growing nearby includes a cautionary note that it was originally labelled C. libani, so perhaps a modicum of suspicion should be applied to both. A more reliable record is of a Glauca Group tree at Bodnant, planted in 1902 and measured at 37.5 m in 2016 (Tree Register 2019).
A healthy number of Atlas Cedars sensu lato comfortably exceeding 30 m height are recorded from across the United Kingdom and Ireland, widely distributed from the Scottish Highlands south to Devon, across the island of Ireland, and from mid-Wales east to Essex. The largest recorded diameter is a tree in Stratford Park, Stroud, which was 2.18 m dbh in 2014. Some of the best in Scotland can be glimpsed from the A9, in the avenue that lines the west drive to Murthly Castle, Perthshire, where two trees had reached 1.84 m dbh by 2017 (Tree Register 2019).
As was explained in the generic article, many remarkable records of both Atlas and Lebanon Cedar from around the world cannot be discussed in depth here because in most cases we cannot be certain the identification is correct. There are of course a great many excellent examples in continental Europe and many of the records from monumentaltrees.com attest to trees of significant size, furthermore it is clear that some, perhaps many of these will be correctly named, and we may generalise that the Atlas Cedar has reached even greater proportions in various locations in continental Europe than it has in the United Kingdom and Ireland. Its performance in North America is on par: a tree planted in 1917 in the grounds of the California State Capitol Museum, Sacramento, was c. 33 m tall (1.3 m dbh) in 2017 (monumentaltrees.com).
Atlas Cedar probably arrived in North America during the 1840s, but certainly by the end of the 1850s (Jacobson 1996) and quickly became a popular ornamental tree. It is now a common sight in much of the northeast USA and adjacent parts of Canada, and along the western seaboard. One of the most famous grows on the south lawn of the White House, reputedly planted by Andrew Jackson (Jordan 2018) however his dates (presidential term 1829–1837, d. 1845) do not fit comfortably with our knowledge of the discovery of the species and its introduction to cultivation, although it isn’t impossible that he planted it in the early 1840s when he was no longer a serving President.
Some records that we can be entirely confident in, of course, are those from native forests in Morocco. There are three records, all from the Forêt de Cèdres above Azrou, including a tree of c. 40 m height, 2.57 m dbh; one of c. 40 m height, 2.42 m dbh; and c. 40 m height, 2.21 m dbh (monumentaltrees.com). The Forêt de Cèdres is one of the most frequently visited Cedar forests in Morocco and it would be surprising if taller and larger examples did not exist in other less well-known stands, and perhaps in Algeria, too. For various reasons the Cedar forests there are not so well known now as they once were, though Debreczy & Rácz (2011) suggest some of the best stands may be seen on Algeria’s Djebel Babor and Djebel Tababor. It is a point of curiosity that in their account for Atlas Cedar, Elwes and Henry state ‘its distribution [in Morocco] is still scarcely known’ (Elwes & Henry 1906–1913) while nowadays it is the details of the extent and health of Algerian populations that is by comparison poorly understood, as travel to that country from many parts of Europe has become increasingly difficult.
This selection makes a broadly conical tree with off-white new foliage. It was introduced to cultivation c. 1868 but is probably now lost. (Auders & Spicer 2012).
A tree with grey-blue foliage with a narrowly conical crown, and strongly ascending branches, especially when young. In ten years it can grow to 3.5 x 1 m. Originally introduced by the Hillier nurseries in 1956, but only widely available from the early 1960s. (Auders & Spicer 2012; Hatch 2018–2020). Jacobson (1996) suggests this may be a renaming of C. atlantica ‘Glauca Fastigiata’.
Gold Atlas Cedar
Golden Atlas Cedar
Cedrus atlantica ‘Aurea’ makes a slow-growing plant of conical habit, rarely more than c. 5 m tall. The needles are shorter than is typical for the species, golden-yellow-green in winter, grey-green suffused with some yellow in summer. It is most effective in full sun but is prone to scorching. Raised in Boskoop, the Netherlands, before 1900. (Jacobson 1996; Auders & Spicer 2012).
A more vigorous clone than ‘Aurea’, though not necessarily an improvement, ‘Aurea Robusta’ makes a conical tree, stronger growing than ‘Aurea’, with longer needles of a paler yellow. These can have bluish tints to them, especially if it is grown in a shady position. To 2 x 1 m in ten years. Introduced by H. den Ouden & Son Nurseries, Boskoop, the Netherlands, in 1932. (Auders & Spicer 2012; Hatch 2018–2020).
A vigorous selection though ultimately making only a broad, mounded shrub with silver-blue foliage. To 1.8 x 1.5 m in ten years. First listed by Buchholz & Buchholz nursery, Oregon, in 2009. (Auders & Spicer 2012).
An upright tree with wide-spreading, drooping limbs ‘twisting horizontally to the ground’ (Auders & Spicer 2012), to 3 x 1.5 m after ten years. The foliage is richly glaucous to powder-blue. Propagated from a tree in Cheltenham District (Auckland) by Cedar Lodge Nursery, New Zealand, and introduced in 1990. (Auders & Spicer 2012).
An obscure cultivar originally raised by the Sénéclauze nursery, France, before 1867, but probably now lost to cultivation. It is described as being of vigorous growth with silvery blue foliage. (Auders & Spicer 2012).
Described by Auders & Spicer (2012) as ‘A slender pyramidal plant with ascending branches and green needles’ but considered by others, including Larry Hatch (2018–2020), to be synonymous with C. atlantica ‘Fastigiata’.
A selection of markedly pendulous growth and rich green foliage, but failing to form a leader unless properly staked (Auders & Spicer 2012). Larry Hatch (2018–2020) suggests this may belong to C. deodara.
Cedrus atlantica f. fastigiata Rehd.
Cedrus atlantica 'Columnaris'
Cedrus atlantica 'Columnaris Erecta'
C. atlantica ‘Fastigiata’ is a widely grown selection, valued for its strong architectural presence in gardens. Nevertheless it is a somewhat variable entity and plants sold under this name probably represent multiple clones differing in their degrees of ultimate ‘fastigiateness’. Hatch (2018–2020) and Jacobson (1996) treat the names ‘Columnaris’ and ‘Columnaris Erecta’ as synonyms, but given the aforementioned variability it is likely that each is slightly different. Even so, reliable separation in the absence of impeccable records is, to say the least, unlikely, so it seems prudent to follow their example and consider them synonymous here.
Generally speaking plants sold as ‘Fastigiata’ are strongly upright in their youth and for their first few decades, often with quite a ‘spiky’ profile at first, gradually becoming a denser, columnar tree. Annual growth in height is typically c. 30 cm, the foliage is bluer toward the tips, but soon two-toned blue-green, and older needles are greener. Trees can and usually do widen in maturity, taking on a narrowly pyramidal profile. The name ‘Fastigiata’ was originally applied to a selection made by the Lalande Nursery, Nantes, France, before 1890. It was soon circulated through Europe and entered the North American trade in the early 20th century. (Auders & Spicer 2012; Hatch 2018–2020).
A name applied to a tree growing in Windsor Great Park, Berkshire, UK, though few details are known (Hatch 2018–2020).
Blue Atlas Cedar
Cedrus atlantica f. glauca
Cedrus atlantica f. argentea Murr.
The Blue Atlas Cedars are among the most popular large-growing conifers in gardens. Glaucous forms occur in natural populations in all four Cedrus species, but it is the prevalance of these forms in C. atlantica that has propelled this species to stardom. It was from native forests that glaucous forms of Atlas Cedar were first introduced to cultivation, for example by Lord Somers of Eastnor Castle, Herefordshire, UK, who brought seeds home from Algeria in 1845, these yielded distinctly glaucous forms as well as the more typical green, as have most subsequent introductions (see main species account). ‘Blue’ trees were originally treated as f. glauca, an approach that is in no way inaccurate given these forms occur in the wild, but for various reasons this was gradually eschewed in favour of ‘Glauca’.
Both names are still commonly encountered on labels and in catalogues, but now these too are gradually giving way to Glauca Group, which perhaps better reflects the variety of clones that now exist as horticulturists have sought, and continue to seek, the bluest of the blue. As with so many cultivar groups the definition of the Glauca Group is vague. It seems to be relatively strictly applied to full-sized (or nearly full-sized) trees, so, somewhat confusingly, many strikingly blue dwarf and miniature selections such as ‘Sapphire Nymph’ are not included here in many other works. Perhaps it is time for a more inclusive use of the group name.
A clone with glaucous foliage and branches descending but not touching the ground. Selected from a tree in the Jardin Botanique, Nantes, France, after 1958 so the latinised name is illegitimate under the rules of the International Code for the Nomenclature for Cultivated Plants (Auders & Spicer 2012).
Weeping Blue Atlas Cedar
Cedrus atlantica 'Pendula Glauca'
This is a popular cultivar on account of its densely borne branches, which hang vertically, their tips easily capable of reaching the ground, and its silvery blue foliage. This is a striking combination of attributes and plants are often trained over arbours and other structures to great effect, though they can be staked or trained to suit almost any position. It appears to be at its most vigorous in locations with reliable summer heat and has become particularly popular in various parts of North America, where it is often planted as a specimen on lawns or incoporated into landscapes to create a ‘living waterfall’ effect (Hatch 2018–2020). There are records of trees to 15 m tall in European collections. In the early 20th century one in Geneva was 7 m tall with a canopy spread of 11 m, and another in Washington State, US, was 5 m tall and 13 m across. It was origionally selected by the nurseryman L. Paillet at Châtenay, France, before 1900. (Auders & Spicer 2012; Hatch 2018–2020).
A globular, dwarf form selected by Barabits Nursery, Hungary, in 1970. To 70 cm tall after 25 years. (Hatch 2018–2020).
A strongly upright, columnar tree with blue needles, shorter than typical for the species. It was found in a field in Evan Farms, Oregon, US, in 1979, named in 1986, and finally introduced 1988. (Hatch 2018–2020).
Selected from a witch’s broom on a 100 year old tree of C. atlantica Glauca Group growing in the Morris Arboretum, Philadelphia, US, and introduced to the trade in 2017. Described as ‘spreading, tiered, in flat planes, sturdy’ (Hatch 2018–2020).
A name applied in North America to a dwarf clone with pale green foliage, after ten years only 30 x 90 cm. The original plant is apparently in the Sir Harold Hillier Gardens, Hampshire, UK. (Auders & Spicer 2012).
An upright, relatively narrow and slow growinc selection with pastel-blue needles. It is usually multistemmed with strongly horizontal side branches. To 2 x 1 m in ten years. Selected and introduced by Horstmann Nurseries, Germany before 1988. (Auders & Spicer 2012).
Cedrus atlantica 'Silberspitz'
Also selected by the Horstmann Nurseries, Germany, in this case before 1992, ‘Horstmann Silberspitz’ is a plant of narrow, upright habit with cream coloured tips on new growth, contrasting with the typical blue-green needles on older branches. In autumn the youngest shoots take on a ‘burnished yellow’ colouration. To 2.5–4 x 1.5 m in ten years. (Auders & Spicer 2012).
A slow-growing clone of irregular growth. The needles are pale green, relatively thick, and the branches stout. Auders & Spicer give dimensions of 50 x 50 cm in ten years, while Hatch suggests nearly 2 m after 20 years, so perhaps growth speeds up after a while. (Auders & Spicer 2012; Hatch 2018–2020).
Described by Auders & Spicer as ‘A conical plant with long dark green needles’ (Auders & Spicer 2012), which is as detailed a description as any others that exist. We may add that it was raised from seed by William Goddard of Floravista Gardens, Victoria, British Colombia, Canada, and introduced by the end of the 1980s (Jacobson 1996). A sparse write-up on the website of the American Conifer Society suggests it is a dwarf form.
One of a troubling number of extreme dwarfs, this time from a witch’s broom on a tree growing in Australia, selected by Peter Taverna who made the discovery in 1977. ‘A dimunitive bun with tiny blue-green needles. In ten years 20 x 30 cm’ (Auders & Spicer 2012).
Weeping Atlas Cedar
Cedrus atlantica f. pendula (Carr.) Rehd.
Not to be confused with ‘Glauca Pendula’, plain old ‘Pendula’, as its name suggests, lacks a glaucous hue to its foliage and has instead green or grey-green needles. It is rarer but hardier than the much more popular ‘Glauca Pendula’, which has superseded it in almost all applications, and it is also more strongly upright when young, ‘nearly columnar’ according to Jacobson (1996) with branches that are initially erect, later gradually becoming pendulous. It was raised by Moreau of Fontenay aux Roses near Paris, France, before 1875. (Auders & Spicer 2012).
A pyramidal tree with irregularly spreading branches according to Hatch (2018–2020) while Auders & Spicer (2012) suggest it is ‘Very similar to ‘Fastigiata”. It was raised by L. Paillet in France before 1889.
A problematic name in that it has also been used under C. deodara, and duplicate cultivar names in the same genus are not acceptable. Whichever was named first has precedence but this is currently uncertain. Described as ‘A hardy selection with golden needles and blue undertones. In ten years 3 x 1.5 m. Introduced by Hachmann nursery, Germany, in 1984’. (Auders & Spicer 2012).
Probably attributable to the Glauca Group as it forms a large pyramidal tree not unlike the type, ‘Rustic’ is consistently described as having outstanding blue needles. It was introduced by the Monrovia Nursery, California, in 1962 or 1963 and was sold by them until at least 1979. It has possibly fallen into obscurity since then. (Jacobson 1996; Auders & Spicer 2012).
Very similar to its sister seedling ‘Sahara Ice’, but faster growing, ‘Sahara Frost’ makes an upright small tree with entirely white new grown in spring and early summer, later the needles are white near the tips but green below this. In winter the tips darken to a pale grey-green. To 3 x 1.5 m in ten years. Raised and introduced by Bill Janseen of Collector’s Nursery, Washington State, before 1995. (Auders & Spicer 2012; Hatch 2018–2020).
Practically identical to its sister seedling ‘Sahara Frost’, only slower growing, to 2 x 1 m after ten years. (Auders & Spicer 2012).
Cedrus atlantica 'Saphir Nymph'
According to Auders & Spicer (2012) ‘A prostrate, bright blue dwarf-shrub, growing with a layered, flat look. In ten years 25 x 75 cm’. Found before 2000 by Pat McCracken, North Carolina. Exceptionally hardy. (Auders & Spicer 2012).
A selection with silvery-white needles. Raised from seed by Ian Gordon on a farm near Taihape, New Zealand, and distributed by Cedar Lodge Nurseries from 1988. (Auders & Spicer 2012; Hatch 2018–2020).
An upright, vigorous clone which can put on 30 cm of new growth per year. The new growth is white-tipped. It is best grown in part shade to avoid scorching in areas with intense sun. (Hatch 2018–2020).
‘A diminuitive bun with grey foliage’ (Auders & Spicer 2012). Hatch suggests it is extremely compact and slow, likening it to Juniperus communis ‘Echiniformis’ (Hatch 2018–2020). It was found in 1977 as a witch’s broom by Peter Taverna, Australia, on the same tree as ‘Mount Saint Catherine’. That two witch’s brooms from the same parent tree have been seperately named and put into commerce will no doubt irritate the purists, but they may console themselves that it isn’t terribly widely grown.
Another selection derived from a witch’s broom. According to Auders & Spicer (2012) it was found by Günther Horstmann, of Germany, outside an English post office. He later named it after his son, Uwe, in c. 1966. No other works have speculated if this was retaliation for England’s world cup victory over West Germany in that year. It is a slow growing and exaggeratedly prostrate clone with light blue needles and annual growth of just 2–3 cm. (Auders & Spicer 2012).
A clone with young branchlets yellow-cream and irregularly white-variegated, the foliage variably variegated also, but not boldy and notoriously unstable. Raised by Sénéclauze, France, before 1867. (Auders & Spicer 2012). One for only the most dedicated enthusiasts.
Cedrus atlantica 'Wilkman's Green'
A vigorous, large-growing selection, the needles a rich green colour, originally offered by Iseli nursery, Oregon, US in 1982. (Auders & Spicer 2012).