Cedar

Cedrus spp.

1. Identification and origin

Cedars (Cedrus spp.) are evergreen conifers of the Pinaceae family, native to the mountainous regions of the eastern Mediterranean and the Himalayas. The main species are Cedrus libani A. Rich. (Lebanon cedar), Cedrus atlantica (Endl.) Manetti ex Carrière (Atlas cedar) and Cedrus deodara (Roxb. ex D. Don) G. Don (Himalayan cedar). They are widely used in ornamental and forestry planting due to their majestic stature and high longevity.

2. Economic importance

Cedar wood is aromatic, resistant and durable, being used in carpentry, joinery and structural applications. In landscaping, cedars are valued as large trees for parks, gardens and alignments. They also have ecological importance as structuring species in mountain ecosystems.

3. Botanical characterisation

Large trees, able to reach 30–50 m in height, with a robust trunk and an initially conical crown, becoming more irregular with age. The leaves are needle-like, grouped in short shoots, with colouring varying between green and bluish-grey. The cones are erect, ovoid, disintegrating on the tree to release winged seeds. The root system is deep, providing good wind resistance.

4. Soil and climate requirements

They prefer temperate to mountain climates, with dry summers and cold winters. They develop best in deep, well-drained, slightly acidic to neutral soils. They are sensitive to waterlogging and soil compaction. They tolerate drought well after establishment, but young plants benefit from supplementary irrigation.

5. Main pests

• Aphids (Aphididae): honeydew and reduced vigour.
• Scale insects (Coccidae): sap-sucking and sooty mould.
• Defoliating caterpillars (Lepidoptera): foliar damage.
• Xylophagous insects (Coleoptera): boring in weakened wood.
• Pine processionary moth (Thaumetopoea pityocampa): may occur on cedars, causing partial defoliation.

6. Main diseases

• Cankers (Sirococcus spp., Diplodia spp.): necrosis on branches and decline.
• Armillaria (Armillaria spp.): root rot in poorly drained soils.
• Rusts (Uredinales): occasional leaf spots.
• Root rots (Phytophthora spp.): rapid decline in waterlogged soils.

7. General crop management

Management includes the selection of species and cultivars adapted to the local climate, maintenance of well-drained soils, moderate pruning and removal of dead branches. Monitoring of sucking pests and of canker symptoms is essential. Avoiding unnecessary wounds and ensuring good drainage significantly reduces the incidence of root diseases.

Bibliographic references

• EPPO Global Database – Cedrus spp..
• CABI Invasive Species Compendium – Cedrus spp..
• Roloff, A. (2013). Trees of Europe. Ulmer Verlag.
• Dirr, M. A. (2009). Manual of Woody Landscape Plants. Stipes Publishing.
• Mitchell, A. (1974). A Field Guide to the Trees of Britain and Northern Europe. Collins.