The North Pole Arborvitae, formally known as Thuja occidentalis ‘Art Boe’, is a popular cultivar prized by landscapers for its distinctive, narrow profile. This evergreen is frequently selected for its ability to create dense, year-round screens and vertical accents in spaces that cannot accommodate wider shrubs or trees. Understanding its growth characteristics is important for anyone planning to integrate this columnar variety into a garden or yard.
Defining the North Pole Arborvitae’s Growth Rate
The North Pole Arborvitae is classified as a slow-to-moderate grower, which is an advantage for landscape planning. Under favorable conditions, the plant achieves an average annual vertical gain of 12 to 18 inches per year. This rate provides noticeable progress over a few seasons but remains manageable in a confined space.
The moderate pace of growth distinguishes it from faster-growing screens, offering a predictable development trajectory. This characteristic is desirable for homeowners who need a permanent, narrow boundary that will not quickly outgrow its designated area. The genetically programmed growth rate helps the cultivar naturally retain its slender shape, meaning the plant invests its energy into creating dense foliage rather than rapid, sprawling height.
Mature Dimensions and Form
The moderate growth rate determines the eventual size and shape of the North Pole Arborvitae. This cultivar matures into a distinctly narrow, columnar, or pyramidal form, which is its primary appeal for modern landscaping. The typical mature height is between 10 and 15 feet, providing substantial vertical presence.
The mature spread remains contained, generally reaching only 3 to 5 feet wide. This tight, upright habit allows it to be used effectively as a vertical accent or a privacy screen in narrow side yards. The slow expansion in girth means the plant maintains its elegant silhouette without requiring frequent pruning. This natural, low-maintenance form is a consequence of its disciplined growth rate.
Environmental Factors Influencing Growth
While the growth rate is genetically determined, the North Pole Arborvitae requires optimal environmental conditions to achieve its maximum annual potential. The plant performs best in full sun, meaning at least six hours of direct sunlight daily. Although it can tolerate partial shade, insufficient light often results in a less dense canopy and a slower overall growth rate.
Soil type and moisture levels also affect the plant’s health and speed of development. It thrives in well-drained soil that remains consistently moist, as the species is native to cooler, damper regions. Allowing the soil to become dry for extended periods, such as during a drought, will significantly slow growth and cause foliage stress. Conversely, planting in heavy, saturated soils that retain standing water will inhibit root function and stunt development. Providing these optimal conditions—sufficient sunlight, consistent moisture, and well-draining soil—is necessary to ensure the North Pole Arborvitae reaches the upper end of its 12 to 18-inch annual growth range.