Garden Scheme
Plant library · Conifers & Evergreens
Thuja occidentalis
Arborvitae is a dense, evergreen conifer that brings year-round structure to larger beds and boundary plantings. At about 30 feet tall and 12 feet wide at maturity, it reads as a substantial vertical element rather than a small foundation shrub. Use its persistent foliage to define the edge of a property, back a broad planting bed, or create privacy where a living wall can remain in place through every season.
Space Arborvitae 8 ft apart, measured center to center (2.4 m).
The mature spread is about 12 ft (3.7 m), so plants set at that distance grow together into a connected screen.
Treat 8 ft as a planning baseline — cultivar and local growing conditions shift the final footprint.
Place arborvitae along a property line or at the rear of a deep bed, where its eventual height will not block wanted views or crowd overhead utilities. A repeated row can make a continuous screen, but keep its long-term bulk clear of gates, service areas, and narrow side yards. Set the planting line far enough from paths and structures that the mature canopy does not turn routine access into a tight passage.
Space plants 8 feet apart, center to center, for a close, connected screen. Each plant can ultimately spread about 12 feet wide, so the row will become visually solid as branches meet and overlap. Reserve the full mature width on the garden side when laying out paths, seating, or lower planting layers; a narrow strip beside the row will be difficult to maintain once the screen fills in.
Give arborvitae a full-sun position and moderate, steady moisture rather than a site that routinely dries hard. Moist, well-drained soil suits a long-lived screen, especially where runoff is not trapped around the roots. In a mixed border, place it where neighboring plants will not compete heavily for the same limited water supply as the trees establish.
Evergreen foliage keeps the planting line present in winter, so the screen continues to shape views and enclose the garden after surrounding perennials die back. In exposed or windy positions, foliage can discolor in winter, and heavy ice or snow can break stems. Keep the row out of wind funnels and leave enough room to inspect the plants after winter weather.[1][2]
This is a large species, and its size should be planned as a permanent boundary feature rather than a temporary fill-in. Avoid dry, exposed sites and deep shade: dry conditions are poorly tolerated, while shade can thin the foliage that gives a screen its density. Deer browsing can also be a serious concern where deer regularly move through the garden.[1][2]