Outbreaks of fungus-like ramorum disease have been known to affect cedar trees. Once a tree is infected, its needles wilt and turn grey or blackish before dying followed possibly by the death of the entire tree in a matter of months; the only way to contain the disease is to fell the surrounding plants within an area of 15 to 20 hectares, otherwise the spread of disease can become a major concern.
Many horticulturalists treat the Atlas Cedar as a subspecies of the Lebanon Cedar; all cedars have layered evergreen foliage though the needles of the Atlas are slightly greyer than the Lebanon which also has level branches.
Phytophthora ramorum was first noted in the UK in 2002 and has since affected many plants, trees and horticulture; aerial survey teams have been used to help the Forestry Commission pinpoint the spread of this killer disease.
Atlas Cedars form forests at an altitude of between one and two–thousand metres. They provide the habitat for the endangered Barbary Macaque often referred to as a “Barbary Ape” because of the small population in Gibraltar, though they are definitely monkeys not apes.
Common in parks and gardens in the UK, the most likely seen variety of this tree has greyish, blue needles that are shorter than those of the Lebanon. Both trees however, still grow clumps of rosettes and have an upright male flower.
Atlas cedars are frequently found in Britain, thus they were introduced to the UK in 1841, some two-hundred years after the Cedar of Lebanon; both of which have similar height and the cedar trees are conifers meaning they are cone-bearing.
To identify an Atlas Cedar try looking at the direction in which the branches grow: Atlas’s branches ascend, Lebanon branches are level and Deodar droop.
All cedar trees flourish in hot dry conditions like many conifers but can survive in wet, cold and even polluted environments; after 150 years of age the branches rot, become more susceptible for disease and fall without warning so the trees do need replacing. Doesn’t the appearance of these large, almost exotic wonders of nature, look quite unmistakable?
There is a healthy Atlas Cedar growing above the old fashioned red telephone box at the lower end of Crystal Palace Park in South-East London and another in the grounds of the White House where Jimmy Carter had a tree house built for his daughter. Designed by the President himself, this infamous Atlas Cedar thankfully is self-supporting and not causing the tree any damage!