A large versatile group of low-growing, spreading or tall erect coniferous trees and shrubs with aromatic, evergreen needle-like leaves and small round fruits.
Botanical Name: Juniperus
Common Names: Juniper
Foliage: Evergreen, aromatic, needle or scale-like leaves. Can be green, grey, blue or yellow in colour.
Cone: Female plants produce berries (cones) that ripen gradually over two or three years. Turning from green to black, with a bluish bloom.
Soil: Moist but well-drained or well-drained soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Full sun or partial shade, in a south, west or east facing aspect.
Habit: Spreading, columnar or bushy depending on variety.
Type: Shrub or tree.
Origin: Northern temperate regions.
Toxicity: Foliage can cause skin reactions so wear gloves and protective clothing when handling. Juniper berries have various documented side effects and the berries of some species, such as J. sabina, are toxic.
Hardiness: Fully hardy in the UK.
Plant early in autumn or mid-spring. Thrives in any well-drained soil including dry or chalky soils. Best in full sun but will tolerate light shade.
Low growing forms are useful as ground cover, in containers or as rock garden plants.
The ripe berries of J. communis have a strong, sharp, aroma and are used commercially to flavour gin.
Water well and spray foliage in dry weather until well established. Shelter from strong winds when young.
Susceptible to attack by aphids, juniper scale and caterpillars. Can be affected by phytophthora, canker and honey fungus.
Increase from seed or take semi-ripe cuttings in early autumn.
Juniperus chinensis (Chinese juniper) is a variable evergreen tree or compact shrub with dense scale-like, dark green foliage. Cultivars include:
Juniperus communis (common juniper) is a variable evergreen shrubby conifer that has several good compact upright garden forms:
Juniperus sabina 'Tamariscifolia' (tamarisk-leaved savin) is a useful compact, low growing juniper with bright green leaves. Often used as ground cover. Height 3ft (90cm), spread 6ft (2m).
Juniperus scopulorum 'Skyrocket' (rocky mountain juniper) a slow-growing pencil-shaped conifer with grey-green scale-like leaves. Height to 20ft (6m), spread 14in (35cm).
Juniperus squamata 'Blue Star' (flaky juniper) a dwarf evergreen conifer that makes a low hummock of silver-blue narrow leaves. Height 16in (40cm), spread 3ft (90cm).
Juniperus virginiana (pencil cedar) is a tall, thin conifer from North America, with grey-green scale-like leaves. Height to 100ft (30m). The popular cultivar 'Grey Owl' is a dwarf columnar form with silver-grey foliage. Height 3-4ft (90cm-1.2m), spread slightly more.