The Weeping Blue Atlas Cedar, or \(Cedrus\) \(atlantica\) ‘Glauca Pendula’, is a striking evergreen conifer prized for its icy-blue foliage and gracefully drooping branches. Unlike most trees, this cultivar inherently lacks a strong central leader, meaning it does not naturally exhibit apical dominance. Left untrained, the tree’s growth habit is prostrate or sprawling, forming a dense, serpentine groundcover rather than an upright specimen. Active structural training is necessary to achieve the soaring, waterfall-like form desired in most landscapes. This intervention establishes a permanent vertical trunk that supports the cascading growth as the tree matures.
Establishing the Central Leader and Support
The first step in training this cedar is to select and secure a single, vertical shoot to act as the permanent trunk or central leader. This leader must be the highest, most vigorous branch capable of being trained upward. Since the trunk is initially flexible and weak, a robust support system is necessary to maintain verticality.
The support should consist of a strong stake, such as a wooden post or heavy-gauge metal pole, driven firmly into the ground next to the cedar’s base. This stake needs to be tall enough to reach the desired final height of the tree, or at least tall enough to support the leader’s growth for several years. As the selected leader grows, it must be secured to the stake at regular intervals, typically every 12 to 18 inches.
The material used for securing the leader must be flexible and wide, such as tree-tie webbing or heavy jute, to prevent damage to the bark. Avoid using thin wire or rope that could cut into the vascular tissue, causing girdling which disrupts the flow of water and nutrients. The ties should be checked annually and loosened immediately if they begin to constrict the expanding trunk. The central leader must be trained in this manner until the tree reaches its intended height, which can range from 10 to 30 feet.
Shaping and Pruning Weeping Branches
Once the central leader is established, focus shifts to managing the lateral, weeping branches for health and aesthetics. Pruning serves two primary goals: maintaining the tree’s health through thinning and enhancing the cascading silhouette through reduction cuts. Thinning cuts improve air circulation and light penetration into the dense canopy, preventing fungal issues.
When thinning, remove entire branches that are crossing, rubbing, or growing back toward the trunk, cutting them cleanly at the point of origin or just outside the branch collar. This selective removal opens the canopy without altering the overall shape. Reduction cuts are used for aesthetic shaping to control the spread of weeping growth and encourage downward flow.
To redirect a lateral branch growing too far outward, cut it back to a side branch or a bud facing downward or inward. If needed, make a cut just above an upward-facing bud to encourage a slight upward turn, though this is used sparingly to maintain the weeping habit. When shortening a long weeping branch, cut back to a healthy side shoot to preserve a natural appearance, avoiding blunt stubs.
Never remove more than one-third of the tree’s total foliage in a single season, as this can severely stress the conifer and inhibit recovery. Focus on making clean, precise cuts with sharp tools to promote rapid healing and minimize the risk of disease entry. The goal is to create a well-defined, cascading curtain of foliage that showcases the unique structure of the trained trunk.
Essential Timing, Tools, and Ongoing Care
The timing of pruning significantly impacts the tree’s health. The best time for major structural pruning and thinning is during late winter or early spring, just before the onset of new growth. Pruning during this dormant period minimizes stress on the tree and reduces the risk of excessive sap loss.
Lighter, aesthetic shaping or trimming of new growth can be done in mid-summer after the initial flush has hardened. Tools needed include sharp bypass pruners for smaller branches, loppers for branches up to two inches, and a fine-toothed pruning saw for thicker wood. Ensure all tools are clean and sterilized before use to prevent the transmission of pathogens.
Ongoing care revolves around the structural support and stability of the trunk. The flexible ties securing the central leader must be inspected annually to ensure they are not becoming restrictive as the trunk girth increases. If the ties are tight, they must be immediately loosened or replaced with a new, wider material. The main support stake should remain in place until the trunk can stand independently, which typically takes five to seven years.