It is a large growing evergreen tree that grows up to 60 m
(197 ft) in height or more, with trunks 1.2–2 m (4–7 ft) in diameter. It is
best known as a fairly slow growing, narrow crowned tree, densely foliaged to
the base, short branched with pendulous ends, one or more drooping leaders, a
tendency to fork,, and with thin foliage, often sold to florists for decorative
purposes and the making of wreaths.
The spray-like foliage, which resembles the flattish fronds
of a fern, surrounds the shoots, so that no buds are visible and is made up of
overlapping scale-like needles (more correctly, leaves) of two kinds – broad,
but less so than Thuja plicata on the flat surface, longer and narrow on the
edge of the shoots. The shiny upper surface is usually medium- or bluish-green,
but may be of other shades of green or yellow. The lower surface has a bloom of
white wax. When crushed the shoots give off a strong smell resembling parsley.
The flowers of both sexes are found of the same tree. They
are usually numerous and appear in March. The small, crimson and conspicuous
males are tiny and club-shaped, and scatter their pollen at the end of March or
in early April. The small globe-shaped females are yellowish-green, with dark
tips to the scales. They soon swell to small berry-like round cones (somewhat
like a pea, but with flat-topped segments), about 1 cm in diameter, light green
with a grey bloom, later ripening to blue-grey or reddish-brown and opening to
shed their small brown seeds in early autumn.
At first the bark is thin, greyish-brown and smooth and
shiny. Later it becomes reddish-brown, irregularly fissured and peels in thin
strips or flakes; within is a bright pink bark. The sapwood is yellowish-white,
the heartwood grey to dark brown. It is strong, light and naturally durable,
and is valuable for joinery and fencing.
A popular hedge plant and ornamental, the tree is going out
of favor with foresters because of its slow growth, low volume, a tendency to
fork.
