Western juniper

Synonyms: Juniperus grandis R.P. Adams, Sierra juniper

Western juniper (Juniperus occidentalis Hook.) – a species of plants of the genus Juniper (Juniperus) of the cypress family (Cupressaceae). It was first described in 1838 by the English botanist and traveler Joseph Dalton Hooker in his book "Fl. bor.-amer".

In nature it grows in the mountainous regions of North America (Idaho, Oregon, Washington, California, Nevada). It occurs at elevations of 800-3000 m above sea level. It germinates on dry rocky sites. It is outcompeted by yellow pine and Pseudotsuga menziesii. The oldest specimen is about 3000 years old (Stanislaus National Forest, California).

It is a monoecious or dioecious shrub or tree 26-30 m in height with a single trunk. Crown rounded or conical. Bark reddish-brown or brown, peeling in thin strips. Small twigs 5-10 mm in thickness, smooth. Branches covered with peeling scales or flakes. Branches grow horizontally or vertically, branchlets straight, in cross-section 3- or 4-angled, constituting up to 2/3 of the length of the scale leaves.

Foliage green, arranged on the stem oppositely in two pairs decussate or in threes around the stems. Glands on the lower side oval or elliptic in shape, well distinct, with yellow or white secretions and with marginal teeth. Mature foliage scaly, 1-3 mm long (on the main shoot may reach 5 mm) and 1-1.5 mm wide, not overlapping, rounded, often acute, less often blunt at the tips. On young seedlings the foliage is needle-like, 5-10 mm long.

Cone-berries 5-10 mm in diameter, blue-brown, covered with a waxy bloom. They ripen once every two years, with 1-4 brown seeds inside 2-4 mm long. Male cones 2-4 mm long, release pollen in early spring. Cones mature in mid-September.

Varieties:

• Juniperus occidentalis var. occidentalis ( Sabina occidentalis Antoine)
• Juniperus occidentalis var. austrális (Vasek) A.H.Holmgren & N.H.Holmgren

Hardiness: 3-9 (-34°C)

Site: drought-tolerant, sun-loving, practically undemanding of soil, resistant to smoke and air pollution.

Planting: recommended spacing between plants 0.5 or 1.2-2 m. Planting depth – 70 cm. Drainage if necessary: crushed brick or sand layer 15-20 cm. Soil mix: topsoil, peat and sand in ratio 1:2:1. Does not tolerate transplanting well, even with a root ball.

Care: in spring in April-May apply nitroammofoska 30-40 g/m2. In dry summers it is recommended to water the plant 2-3 times per season and carry out evening spraying once a week. Mulch with peat or sawdust to a depth of 5-8 cm.

Pruning: tolerates heavy pruning and clipping well, retains its shape for a long time.

Diseases: rust (Arcerid (50 g per 10 l of water) spray 4 times at 10-day intervals), Schütte, biatorrell and Nectria canker, alternariosis, root cancer (Oligotrophus betheli).

Pests: aphids (Fitoverm (2 g per 1 l of water) spray 2 times at 10-14 day intervals), leaf-mining moth (Decis (2.5 g per 10 l) spray 2 times at 10-14 day intervals), spider mite (Karate (50 g per 10 l)), scale insects (carbophos (70 g per 10 l of water)), galls, sawfly, shoot moth, pine looper.

Propagation: propagated by seeds, not vegetatively.

Uses: not used in ornamental gardening. The wood is very strong and resistant to rot. Used for the production of particleboard, plywood and other wooden products. Can be used for growing in bonsai style.