When landscaping a property in cooler climates, the choice between a green giant arborvitae and other evergreen options often comes down to specific goals. These two plants, while frequently grouped together in the nursery trade, serve distinct roles in the garden. Understanding the nuanced differences between the rapid growth of the Thuja plicata 'Green Giant' and the classic form of Thuja species is essential for long-term satisfaction.
Defining the Contenders: Botany vs. Cultivar
The primary distinction lies in their biological classification. The term "green giant arborvitae" is a marketing name for a specific cultivar: *Thuja plicata* 'Green Giant'. This means it is a selected variant of the Western Red Cedar species, bred for desirable traits. In contrast, "Thuja" is a broad genus encompassing several species, including *Thuja occidentalis* (Eastern White Cedar) and *Thuja koraiensis* (Korean Arborvitae). When comparing the green giant to the general category of Thuja, you are essentially comparing a fast-growing hybridized cultivar to a wider family of slower-growing, often more ornamental evergreens.
Growth Rate and Final Dimensions
One of the most significant differentiators is velocity. The *Thuja plicata* 'Green Giant' lives up to its name, capable of adding 3 to 5 feet of height annually during its early years. This rapid screen establishment is a major advantage for homeowners needing quick privacy. Mature specimens can reach staggering heights of 40 to 60 feet with spreads of 12 to 15 feet. Conversely, standard Thuja species like *T. occidentalis* are much more restrained. They typically max out between 15 to 20 feet tall and 8 to 10 feet wide, making them more suitable for residential lots where space is a premium.
Size Comparison at a Glance
The Visual and Textural Experience
Looking beyond the numbers, the aesthetic qualities differ. The green giant arborvitae features a classic pyramidal shape with dense, scale-like needles that maintain a vibrant green color year-round, often with a slight bronze tint in winter. Its foliage is soft to the touch. Standard Thuja, depending on the species, can offer more variety. *Thuja occidentalis* 'Rheingold', for example, provides striking golden-yellow foliage in spring that ages to bronze, adding seasonal interest that the uniform green giant lacks. While the green giant offers a dense, uniform screen, other Thuja varieties provide textural diversity through varied foliage colors and growth habits.
