Atlas cedar ‘Glauca’ is an evergreen atlas cedar named for its characteristic blue-green Needle-shaped leaves which differ markedly from the paler leaves of its parent tree. This cultivar originated in the Atlas mountains of North Africa and was introduced to France in the nineteenth century.
I. Appearance and Characteristics
Highly popular, Cedrus atlantica ‘Glauca’ (Atlas Cedar) is a large evergreen coniferous tree of conical habit and sparsely branched when young, but develops into a dense and broad pyramid over time.
The leaves of atlas cedar ‘Glauca’ are narrow, blue-gray needles arranged in spiral formations around the branches. Each needle is thicker and more stout compared to other cedars, measuring approximately 0.75 to 1.25 inches (2 to 3 cm) in length. The needles have a smooth texture and exhibit a distinguished silvery-blue hue, which adds a striking contrast to the plant’s overall appearance. This unique coloration and robust needle structure make the leaves of atlas cedar ‘Glauca’ easily identifiable.
Atlas cedar ‘Glauca’ flowers are inconspicuous and non-showy. They are characterized by small, erect, barrel-shaped cones that measure approximately 2 to 3 inches (5 to 7.5 cm) in length. The cones are typically green or purplish in color when young, maturing to a brown hue. The blooming period occurs in the spring. Unlike more prominent flowering plants, atlas cedar ‘Glauca”s floral structures are subtle, an aspect key to its identification.
The fruit of atlas cedar ‘Glauca’ is characterized by its large, woody cones, which each typically measure 3 to 6 inches (7.6 to 15.2 cm) in length. They have a distinctive barrel shape with a slightly tapered end, exhibiting scales that are tough and closely packed. The color of the mature cones transitions to a deep, rich brown tone, providing a contrast to the blue-green foliage. Texturally, the cones are rigid, with a rough surface that provides adherence for seed dispersal. The cones take a considerable amount of time to mature, often remaining on the tree for several years before releasing their seeds.
II. How to Grow and Care
Sunlight
Atlas cedar ‘Glauca’ does best in full sun or partial shade. You should plant your atlas cedar ‘Glauca’ in a location that receives a minimum of four hours of direct sunlight per day.
Temperature
Atlas cedar ‘Glauca’ is quite cold-tolerant but should only be planted where winter temperatures stay above -18 ℃. It’ll tolerate some drought once established but may need to be watered in periods of extreme heat and drought. In soggy soil, atlas cedar ‘Glauca’ is susceptible to root rot.
Watering
Originating from the Atlas Mountains, atlas cedar ‘Glauca’ is accustomed to a moderate climate with periodic rainfall. This species exhibits drought tolerance once established and prefers a balance of moisture without being waterlogged. For optimal health, watering every week is recommended. Typically grown outdoors due to its size and growth habit, atlas cedar ‘Glauca’ thrives in well-draining soil that mimics its native mountainous terrain; this is crucial for preventing root rot and ensuring proper hydration.
Soil
Atlas cedar ‘Glauca’ is easy to please and can be grown in a variety of soil types, including clay, sand, and loam. The tree thrives in moist and well-drained soils and will tolerate some drought too. Atlas cedar ‘Glauca’ also tolerates a wide range of soil pH levels, from strongly acidic to mildly alkaline, or a pH between 5.1 and 7.8.
Fertilizing
To sustain atlas cedar ‘Glauca”s health and growth, utilize balanced nutrition fertilizers once annually, ideally in spring. This annual fertilization bolsters root, stem, and foliage development, contributing to overall vigor. Use fertilizers labeled as ‘evergreen’ or ‘tree and shrub’ formulas, respecting the suggested quantities to prevent root burn. Seasonal growth variations dictate lesser quantities for young atlas cedar ‘Glauca’s, encouraging gradual, strong growth. Always water thoroughly post-fertilization to distribute nutrients. Novices should opt for slow-release granules for controlled feeding, ensuring safe, effective nutrient uptake.
Planting Instructions
To plant your atlas cedar ‘Glauca’, select a site with full sun or partial shade and dig a hole slightly larger than your tree’s pot or root ball. For best results, add some compost to the hole. Place your tree in and fill in around it, ensuring that the soil is at the same level as it was in the pot. Firmly pack soil around the roots and pack down the final layer with your feet. Water your atlas cedar ‘Glauca’ in well.
Pruning
If you have the space to let your atlas cedar ‘Glauca’ grow, there’s no need to prune. However, the tree can be pruned in early spring before it begins putting on new growth. You can prune to shape it or to prevent it from growing too close to structures or other trees. You can also prune dead or damaged limbs.
When pruning, always sanitize your pruning saw in between trees. This can help prevent the spread of fungal diseases and bacteria from tree to tree.
Propagation
Atlas cedar ‘Glauca’ is a distinctive conifer known for its silvery-blue needles and majestic stature, often used as a bold landscape specimen. When propagating atlas cedar ‘Glauca’, semi-hardwood cuttings are favored, ideally taken from the current season’s growth. Clean, sharp tools are crucial to prevent disease and to ensure a clean cut. Rooting hormone can enhance the chances of successful rooting, and maintaining consistent moisture and warmth in a well-draining medium promotes root development. Patience is essential, as atlas cedar ‘Glauca’ may take several months to establish a strong root system.
Transplanting
Atlas cedar ‘Glauca’ thrives when transplanted in the rejuvenating warmth of early spring or the settling coolness from mid to late fall. Opt for a sunny, well-draining location. Avoid waterlogged soils to ensure robust root establishment.
III. Uses and Benefits
This tree produces an aromatic oil that is a natural insect deterrent. Its harvested wood is commonly used in building furniture and drawers.