The growth rate of a cedar tree is highly variable because the term “cedar” is used for many different species. The rate depends on the tree’s true botanical identity and its specific growing conditions. All trees commonly called “cedar” share a long lifespan, often ranging from centuries to over a millennium. This longevity usually corresponds with a slow to moderate growth habit over the tree’s full life cycle.
Defining Cedar: True Species Versus Common Names
The growth cycle of a cedar tree depends on whether it belongs to the true cedar genus, Cedrus, or one of the many North American conifers that share the common name. True cedars, such as the Cedar of Lebanon (Cedrus libani) and the Deodar Cedar (Cedrus deodara), are native to the Mediterranean and the Himalayas. These species are known for their immense size and long lives.
In North America, trees called cedars are usually members of the cypress family (Cupressaceae), and their growth characteristics differ significantly. For example, the Eastern Red Cedar (Juniperus virginiana) is botanically a juniper, and the Western Red Cedar (Thuja plicata) is a type of arborvitae. Understanding this distinction is essential because the growth rates between true and false cedars can vary by a factor of three or more. North American species are generally faster-growing and more adaptable than the true cedars.
Measuring Growth: Annual Rates and Time to Maturity
Cedar trees exhibit a growth pattern that is initially moderate to fast, followed by a significant slowdown as they near their mature height. True cedars, such as the Deodar Cedar, typically display a medium growth rate. Under optimal conditions, they add between 12 and 24 inches of height per year, eventually reaching 50 to 70 feet.
The growth speed of “false cedars” is more pronounced, offering a faster solution for landscaping needs like privacy screens. The Eastern Red Cedar maintains a moderate pace of 12 to 24 inches per year for the first 30 years before its growth rate slows dramatically. This species can reach a mature height of 40 to 50 feet. A young Eastern Red Cedar may reach a usable height of about eight feet in as little as five years with proper cultivation.
The Western Red Cedar is one of the fastest-growing options, often adding 24 to 36 inches of height annually. This species is commonly chosen for hedges and privacy screens because it reaches a significant, practical height more quickly than other varieties. Although it is faster to reach a usable size, all cedars are long-lived, with some Western Red Cedar specimens documented to have lived for over a thousand years.
Key Environmental Influences on Growth Speed
The maximum growth rate a cedar achieves is heavily influenced by site-specific environmental conditions. Sunlight exposure is a primary factor, with most species requiring at least six hours of direct sun daily for maximum photosynthetic activity. The Eastern Red Cedar is intolerant of shade and will exhibit sparse, stunted growth if not planted in a full-sun location.
Soil composition and moisture are equally influential, and requirements vary significantly by species. The Western Red Cedar thrives in consistently moist, well-drained soils rich in organic matter, preferring an acidic to neutral pH. This species suffers from drought stress and dry winds, requiring supplemental watering outside of its native Pacific Northwest habitat.
In contrast, the Eastern Red Cedar is remarkably drought-tolerant once established and thrives across a wide range of soil types, from acidic to alkaline. This resilience allows it to flourish in difficult growing conditions, such as rocky or limestone-based soils, which often have a circumneutral pH. True cedars, like the Deodar Cedar, also require well-drained, often loamy soil with a slightly acidic to neutral pH. They will not tolerate standing water or poorly drained clay that leads to root rot.
Maximizing Growth Through Cultivation Techniques
Homeowners can promote faster growth by adhering to a specific watering schedule, especially for young trees. New cedar transplants, such as the Eastern Red Cedar, benefit from an intensive initial watering routine. For example, applying two gallons of water per inch of trunk diameter daily for the first two weeks helps the tree establish a healthy root system, which is the foundation for vertical growth.
Lack of sufficient water is a common hindrance to a young cedar’s growth, even in species that are drought-tolerant once mature. After establishment, deep weekly watering is beneficial, allowing the surface soil to dry slightly between applications. Applying three inches of organic mulch around the tree’s base helps conserve moisture and suppress weeds. However, keep the mulch several inches away from the trunk to prevent rot.
Fertilization is generally unnecessary for mature, established cedars, but a light application can boost the growth of younger trees. A balanced, slow-release fertilizer, such as a 10-10-10 ratio, can be applied once annually in early spring to support new growth. Strategic early pruning or shaping can also increase the overall vigor and density of the canopy, indirectly contributing to the faster development of a full, screen-ready tree.