Incense Cedar (Calocedrus decurrens) offers a rewarding journey for bonsai enthusiasts. This evergreen conifer, native to the western United States, presents unique characteristics that translate beautifully into the miniature art form. Its distinctive scale-like foliage, which can be finely ramified, and its attractive reddish-brown bark contribute significantly to its aesthetic appeal. The natural upright growth habit of the Incense Cedar, combined with its inherent hardiness, makes it a compelling choice for cultivating a living sculpture.
Why Incense Cedar for Bonsai
Its dense, scale-like foliage allows for fine ramification and detailed canopy pads, which can be refined with careful pinching. The reddish-brown bark develops appealing texture with age, enhancing the trunk’s visual interest. The tree’s naturally upright growth habit supports various bonsai styles, particularly formal and informal upright designs. Incense Cedar also exhibits hardiness and adaptability to different soil types and climatic zones, making it a robust and versatile choice for bonsai.
Basic Care for Incense Cedar Bonsai
Light
Incense Cedar bonsai flourish when exposed to ample sunlight. They prefer full sun exposure, ideally receiving at least six hours of direct sunlight daily. While they can tolerate partial shade, insufficient light may hinder their growth and overall vitality. Placing the bonsai in a location where it receives morning sun and some afternoon shade can be beneficial, especially in hotter climates, to prevent excessive drying of the soil.
Watering
Proper watering is crucial for Incense Cedar bonsai, as they prefer consistently moist but not waterlogged soil. It is advisable to water thoroughly until water drains from the bottom of the pot, allowing the top inch or so of the soil to dry out before the next watering. This approach helps prevent root rot, which can occur if the tree remains in constantly saturated conditions. Watering frequency will vary with season and climate, with more frequent watering needed during warmer months and less during cooler, dormant periods.
Soil Requirements
Incense Cedar bonsai thrive in well-draining, aerated soil mixes. A suitable bonsai soil includes components like akadama, pumice, and lava rock, or a conifer-specific bonsai mix. This substrate ensures proper drainage and aeration, preventing waterlogging and supporting root development. The tree prefers slightly acidic to neutral soil, with a pH range between 6.0 and 7.0.
Fertilizing
Regular fertilization supports vigorous growth and health. During the active growing season (spring through late summer), apply a balanced, slow-release fertilizer every four to six weeks, or as product instructions advise. Reduce or cease fertilization during fall and winter to prepare the tree for dormancy.
Bonsai Training Techniques
Pruning
Pruning maintains the shape of Incense Cedar bonsai and encourages denser foliage. Light pruning, such as pinching new growth, can be done throughout the growing season to promote ramification and maintain pad density. Heavier structural pruning, including removing unwanted or overgrown branches, is best performed in late winter or early spring before new growth hardens. Removing dead or crossing branches also improves air circulation and light penetration within the canopy.
Wiring and Shaping
Wiring allows precise shaping of branches and the trunk. Use copper or anodized aluminum wire, selecting a gauge strong enough to hold the branch without damaging the bark. Incense Cedar branches can be brittle, so apply wire gently to avoid breakage. Wire when the tree is actively growing, allowing branches to set in new positions as they mature. Remove the wire before it cuts into the bark, typically within a few months to a year, to prevent scarring.
Repotting
Repotting maintains root health and provides fresh growing medium. Young Incense Cedar bonsai benefit from repotting every two to three years, while mature specimens need repotting every three to five years. The best time for repotting is early spring, as the tree shows signs of new growth. During repotting, remove a portion of old soil and prune circling or overly long roots by about one-third to encourage a healthy, compact root system.
Common Problems
Yellowing foliage can indicate either overwatering or underwatering, as both conditions disrupt nutrient uptake. It can also signal a nutrient deficiency, suggesting a need for proper fertilization. Pests such as spider mites and aphids may infest Incense Cedar, feeding on the foliage and causing discoloration or stunted growth. Regular inspection of the foliage, particularly the undersides of leaves, can help detect these pests early. Fungal diseases like needle blight or canker can also occur, often appearing as brown patches or dieback of branches. Good air circulation and avoiding overly humid conditions can help prevent fungal issues.
Winter Protection
Protecting Incense Cedar bonsai during colder winter months is essential, especially in regions with freezing temperatures. While Incense Cedar is hardy, its roots in a shallow bonsai pot are more vulnerable to freezing than a tree in the ground.
Winter protection methods include placing the bonsai in an unheated garage, a cold frame, or burying the pot in the ground or mulch to insulate the root ball. This shields the roots from extreme cold and frost heaving. Throughout dormancy, continued, albeit reduced, watering is necessary to prevent the root ball from completely drying out. Keeping the tree hydrated without being waterlogged during winter maintains its vitality until spring.