Incense Cedar (Calocedrus decurrens)

Calocedrus decurrens, commonly known as Incense Cedar, is a stately evergreen tree native to the western United States. Incense Cedar is a valuable species in natural and cultivated landscapes and is renowned for its aromatic wood and graceful form. Here is a comprehensive guide to growing and caring for Calocedrus decurrens:

Incense Cedar is a large conifer that can reach impressive heights. In its native habitat, it may grow up to 60 meters, but it typically reaches 30 to 50 meters in cultivation. The tree has a distinctive pyramidal to columnar shape, with horizontal branches that develop into a dense crown. The spread of Incense Cedar is generally about two-thirds of its height, creating a broad and substantial presence in the landscape.

It thrives in a variety of well-drained soils. It is adaptable to various soil textures, including sandy, loamy, and clayey soils. However, the key is good drainage to prevent waterlogged conditions, which can harm the tree’s health.

While Incense Cedar tolerates different soil pH levels, it typically performs well in slightly acidic and neutral soils. A pH range of 6.0 to 7.5 is considered suitable for optimal growth. Regularly testing the soil pH can help ensure the tree is planted in conditions supporting its health.

It is well-suited to temperate climates. It thrives in areas with cool-to-cold winters and warm-to-hot summers. It is hardy to USDA Zones 4 to 8, making it adaptable to various regions throughout southeastern and eastern Australia. The tree is known for its resilience and can tolerate diverse environmental conditions.

Calocedrus decurrens prefers full sun but can also tolerate partial shade. It typically exhibits optimal growth and form when planted in locations that receive at least six hours of direct sunlight daily. Providing afternoon shade in regions with hot summers can help protect the tree from excessive heat.

Proper watering is crucial during the establishment phase of Incense Cedar. The soil should be kept consistently moist but not waterlogged. Once established, the tree is moderately drought-tolerant and can withstand periods of reduced water availability.

Fertilisation is generally not required if the tree is planted in well-nourished soils. However, in nutrient-poor soils, a balanced, slow-release fertiliser can be applied in spring to promote healthy growth. It’s essential not to over-fertilise, as this can lead to excessive foliage at the expense of overall tree health.

Calocedrus decurrens typically require minimal pruning. Its natural form is symmetrical, and the branches are usually well-spaced. However, removing dead or diseased branches can be done as needed to maintain the tree’s health and appearance. Any pruning should be performed during the dormant season to minimise stress on the tree.

Propagation is primarily achieved through seeds. The seeds are contained within small cones, and collecting them in late fall is the standard method of seed propagation. Seeds should be stratified to break dormancy before sowing. Germination may take several weeks, and young seedlings can be transplanted once they are large enough to handle.

It is highly valued for its ornamental qualities and is commonly planted as a specimen tree in parks, gardens, and larger landscapes. Its distinctive fragrance, attractive foliage, and impressive size make it an excellent choice for creating focal points in the landscape. Additionally, the wood of Calocedrus decurrens is highly durable and resistant to decay, making it desirable for outdoor construction, shingles, and other applications.

The Incense Cedar is a magnificent evergreen tree that enhances the beauty of various landscapes. This conifer prefers well-drained soil, regular watering, and exposure to full sun or partial shade. Whether planted alone or incorporated into a larger landscape design, the Incense Cedar is a durable and long-lasting tree that enchants with its fragrant presence.