Cedars are beautiful, majestic trees that grace parklands and estates across Britain. In particular, the cedar of Lebanon provides a fabulous silhouette, with its flat-topped, tiered branches once mature. It is an ancient tree, referenced in the Bible, that made up great forests of old.
The genus is quite small — just four species, all medium-to-large evergreen trees. Generally they are conical when young but develop a wide trunk and horizontal branches as they age. They have narrow, needle-like leaves and bear both the male and female strobili and cones.
Cedrus libani Award of Garden Merit (AGM), C. atlantica and C. brevifolia are very closely related. Some people classify atlantica as a subspecies of libani, but this article follows the RHS classification, which separates them. The first two can both form very large trees, with brevifolia a little smaller and with smaller needles. C. libani AGM is slower growing than C. atlantica.
C. deodara AGM is the standout species. It has a trailing leader, a gently pendulous habit and soft blue/green foliage. Popular cultivars, include C. atlantica ‘Glauca’ AGM, which has striking blue needles; and C. deodara ‘Kelly Gold’, with its vivid yellow juvenile foliage.
Cedars can be planted on most soil types but they need conditions to be well-drained — they do not cope well with waterlogging. They are also best planted where they get shelter from cold drying winds. They are a tree for which the maxim "right plant, right place" is very appropriate.
Their fast, young growth and eventual majestic size mean they need to be given plenty of space, and are usually planted as specimens in open areas of parks or large gardens.
One issue that affects the establishment of cedars is that they do not transplant well and often lose their needles as a result. This means bare-root and root-balled plants are not recommended. Solutions to this problem are to plant them when very young or ensure they have been grown in Air-Pots at the nursery, because these will have a fibrous root ball and limit the shock. Even if the needles do drop they will produce a new flush of needles later in the year.
Another issue you may want to be aware of is that C. deodara AGM is often used as the rootstock for C. atlantica and C. libani AGM. While this produces a nicely fibrous and compact root system, C. deodara AGM is not as long-lived, so you may be best choosing trees grown from seed rather than grafted plants.
What the specialists say
Jan van Vechel, sales and advice, Van den Berk, the Netherlands
"Cedrus is a tree that has a lot of history. It is found in many large parks and estates. The most wonderful one is the cedar of Lebanon. Its fantastic proud shape can be recognised at some distance.
"Other varieties I like very much are C. deodara, which has nice fresh green needles, develops a decorative crown and has nice pendulous branches. I also like C. libani ‘Fastigiata’, a narrow, pyramidal, dense-growing tree; and C. libani ‘Glauca Pendula’, which can grow into the most incredible shapes when older — very decorative.
"The difficulty when you move these kind of trees is that they can drop needles, sometimes more than 70 per cent. This happens in May/June and depends on temperature and drought. With good maintenance you can reduce this and even when they lose so many needles this will come back after mid June/early July.
"This needle drop is a protection mechanism. If the needles don’t get enough water they will drop. What is important is that the tree will make new fibrous roots that can feed the new needles to bud out."
Mike Glover, managing director, Barcham Trees, Cambridgeshire
"Cedrus is a wonderful and wide-ranging genus of tree that usually grow up to form impressive and imposing specimen trees. Offering a range of colours, textures and shapes, this set of attractive evergreen trees makes distinct and lasting statements on the landscape.
"One of my favourite cedars is C. deodara, the deodar cedar. This stunning tree has a lovely open pendulous shape at maturity and delightfully tactile foliage that looks soft and bright when the new needles appear. There are numerous variations in the colour of its foliage to add further intrigue to this type of cedar.
"When choosing to plant cedars the biggest problem that people tend to have is that they do not allow enough space for them to grow. As a young tree they are quite small, with short lateral branches, giving the illusion of smaller stature, which is quite unfounded. Very large gardens and estates therefore make the perfect backdrop for cedars. Do not plant them in areas prone to waterlogging and sitting wet during the wintertime. Like many evergreens, cedars prefer to be situated on a well-drained soil."
Mark Godden, sales, Deepdale Trees, Bedfordshire
"Cedars are great specimen trees, perfect for parkland settings where there is room to plant and enjoy their mature beauty. My favourite would have to be C. atlantica ‘Glauca’, with its stunning blue foliage.
"Make sure the ground is well-drained. They won’t grow well in waterlogged soils. Also make sure you have the room to plant a cedar. They can grow very large. Many of the cedars are difficult to transplant and can suffer defoliation when moved. For this reason we always recommend planting Air-Pot containerised stock to prevent any transplant shock."
Dan Crowley, dendrologist, Westonbirt Arboretum, Gloucestershire
"Given an organically mulched weed-free area, cedars establish well with us here at Westonbirt. We grow healthy trees on and plant young, to reduce any potential for transplant shock, to aid establishment and to avoid any need for staking. They are quite happy here given most soil types with adequate drainage, though appreciate shelter from cold drying winds.
"Ultimate size is large so trees are best afforded plenty of space and away from the immediate vicinity of buildings. Quick-growing when young, it is wise to site carefully to avoid being caught out later on.
"Though seen often enough, planting trees of C. atlantica Glauca Group is always recommendable, with the blueish to sometimes silvery foliage most spectacular among darker conifers and afforded good levels of sunlight.
"As a single specimen, C. libani takes some beating. However, though long-lived in cultivation, they can be prone to branch breakout after 150 years or so, or as a result of being laden with snow."
Species and varieties
C. atlantica is a large, evergreen tree that comes from the Atlas Mountains of Algeria and Morocco. It is a conical, fast-growing tree when young, later becoming a grand tree with wide horizontal branches. Said to cope better with urban pollution than C. libani or C. deodara. Height: 20m-plus.
C. atlantica ‘Aurea’ AGM (H6) is a medium-sized tree with golden-yellow shorter needles. Not the best grower.
C. atlantica ‘Glauca’ AGM (H6), or the blue cedar, has highly attractive, silvery blue foliage. It is fast-growing and sparsely clothed in needles when young, but thickens out as it ages. Height: 20m-plus.
C. deodara AGM (H6), or the Himalayan cedar, is a beautiful tree that has a lovely pyramidal shape when young that flattens out with age. The dark-blue/green needles are slightly curved and the longest of the cedar species. The cones are reddish brown with a rounded top, borne singly or in pairs. Saplings are sensitive to frost so plant them in a sunny site sheltered from wind. Height: 30m.
C. deodara ‘Karl Fuchs’ is an extremely hardy blue form with good blue foliage. Like the straight species, it has a trailing leader and gently pendulous habit. Height: 20m-plus.
C. deodara ‘Pendula’ AGM is a broad, weeping cultivar with branches hanging down to the ground. Has dark bluish/green needles and upright reddish brown cones. Suits being planted as a solitary specimen tree. Height: 5m.
C. libani AGM (H6) is the cedar of Lebanon, a majestic tree with tiered branches once mature. Has short, stiff needles and upright grey/green cones, borne singly, that later turn brown. Often gracing landscapes, especially parkland, because it needs space to be shown off. Height: up to 40m, usually 20-25m in cultivation.