A tree usually 40 to 50, occasionally 60 to 100 ft high; the bark peeling off in long loose strips. It is pyramidal when young, becoming more round-topped with age. Leaves of both awl-shaped (juvenile) and scale-like (adult) forms on the same tree. The former, arranged in pairs, are 1⁄8 to 1⁄4 in. long, pointed, concave inside and glaucous except on the margins, grey-green and convex outside, pointing forward. Scale-leaves 1⁄16 in. long, ovate, pointed (sometimes slenderly), thickened and convex outside, overlapping. Young specimens have none other than the awl-shaped type of leaf; as they grow older, branches of scale-like leaves appear until, in the adult state, the tree bears scarcely any other, and it is on these that the fruits are borne; fruits, however, are sometimes to be seen on branches bearing an intermediate type of leaf. Male and female flowers are usually separated on different trees, but occasionally appear on the same. Fruits roundish, 1⁄4 in. long, scarcely so wide, covered with a blue glaucous bloom, carrying one or two seeds.
Native of the eastern and central United States and eastern Canada; introduced about the middle of the 17th century. This juniper is by far the commonest and largest of the arborescent species cultivated in gardens. It likes a well-drained soil, is perfectly hardy, and altogether one of the best thriving of eastern N. American trees in this country, especially on chalky soils. From the next most common of tree-like junipers, J. chinensis, this in all its forms is best distinguished by its awl-shaped leaves being nearly always in pairs, and by its scale-like leaves being always pointed. Small plants are like J. sabina, but that to be distinguished by its peculiar rank smell when crushed.
J. virginiana is a variable species in the wild and it is believed that this variability may be due in part to crossing with neighbouring species.
Cultivars of this species are greatly to be preferred to seedlings and unselected plants, which usually become of ugly habit with age. The oldest specimens of these latter are about 35 to 60 ft in height and 51⁄4 to 101⁄4 ft in girth. The number of named cultivars is large, but the following arc the best known and are available in commerce:
‘Burkii’. – Habit fastigiate, dense. Foliage blue-grey, slightly purplish in winter. It has attained a height of 20 ft at the R.H.S. Garden, Wisley.
‘Canaertii’. – Habit columnar. Leaves rich green. Free-fruiting. An example in the National Pinetum at Bedgebury, Kent, pl. 1926, is 34 ft high (1969).
‘Elegantissima’. – Sprays golden at the tips.
‘Glauca’. – Under this cultivar name Van Ouden and Boom (Man. Cult. Conif., p. 200) describe a tree of narrow, columnar habit with thin, round, blue-bloomy branchlets and small glaucous appressed leaves (some leaves inside the plant acicular). But not all the plants that are or have been known by the name J. virginiana glauca belong to this clone.
‘Grey Owl’. – A spreading shrub 3 to 4 ft high and more in width, with silvery grey leaves and slender sprays. Very elegant. It is possibly a hybrid, with J. chinensis ‘Pfitzerana’ as the pollen-parent.
‘Hillii’. – Habit columnar, dense. Leaves glaucous, purplish in winter. Also known as J. v. ‘Pyramidiformis Hillii’ and J. v. ‘Dundee’.
‘Schottii’. – A columnar tree with bright green scale-like foliage.
‘Sky Rocket’. – A very slender fastigiate variety with glaucous scale-like foliage. Some authorities consider that it belongs to J. scopulorum.
‘Tripartita’. – A shrub of low, spreading habit. Leaves mostly acicular, ascending to spreading, their exposed upper sides giving a glaucous cast to the whole plant; lower sides rich green.