Juniper: which varieties are best for covering a slope?

Creeping Junipers - Juniperus horizontalis

These are junipers with a spreading, ground-covering habit, which grow horizontally, as their Latin name Juniperus horizontalis indicates. They form elegant, dense ground-covering carpets, perfect for covering a slope. Evergreen, they remain ornamental in all seasons. In cultivation, they have the advantage of tolerating the harshest conditions, in poor soil, even when occasionally dry and calcareous. They prefer full sun (or partial shade in hot southern regions), as well as well-drained soils that do not retain excess moisture. They are very hardy, not prone to disease and only dislike stagnant moisture.

There are several varieties, differing in foliage colour.

‘Wiltonii’ measures only 20 cm in height, but spreads to nearly 2 metres 50. It is distinguished by its evolving foliage colour. Initially green-grey tinged with blue in summer, it reddens as the temperature drops.

‘Golden Carpet’ forms a true bright vegetative carpet, thanks to its light green foliage with golden tips, which takes on orange hues in winter. It reaches 30 cm in height with a 2 metre span.

For its part, ‘Blue Chip’ prefers to reward us with almost blue-grey foliage, turning bluish-purple in cold conditions. In terms of dimensions, expect 30 cm in height and 2 metres of spread.

‘Limeglow’ is a dwarf variety that never fails to delight. Its new shoots first appear lime green, before expanding to gold, then turning bronze to purple in winter. It grows to just 30 cm high with an 80 cm spread.

‘Prostrata’ will be perfect for covering large slopes after a few years, thanks to its spreading of nearly 3.5 metres.

The variety ‘Blue Chip’

Beach junipers - Juniperus conferta

Juniperus conferta forms beautiful carpets of needles, decorative all year round. Perfect candidates for groundcover use, they will, with ease, clothe a slope over time, even one that’s difficult to establish. They indeed have a prostrate, spreading habit. Also known as beach junipers, sea juniper or shore juniper, they tolerate in fact soil salinity and salt spray very well. These are junipers perfectly suited to coastal gardens, but they can also easily integrate into gardens in regions farther afield. These junipers even thrive in sandy, very poor soil, in full sun. They prove quite hardy as long as the soil is well-drained.

‘Schlager’ measures 30 cm in height with a 2-metre spread. It has handsome green foliage, tinged with silver.

‘All Gold’ stands out with its graceful, pliant sprays of golden-yellow colour, which will take on an orange to bronze hue in winter. A particularly bright variety, reaching 30 cm in height and 1.5 m wide at maturity.

‘Blue Pacific’ produces scaly, flexible sprays, bearing apple-green foliage in spring, which becomes blue-tinged in winter frosts. Expect 30 cm high with a 1.5 m spread.

The Juniperus conferta ‘All Gold’

Scaly junipers - Juniperus squamata

Scaly junipers can take different silhouettes. There are several varieties wider than tall, which will be perfect for eventually covering large areas. They can grow in full sun or partial shade, but tend to prefer fairly cool soils (which never completely dry out). They will not tolerate hot, canicular conditions well. In drained soil, they will, however, show great frost resistance.

C’est le cas du Juniperus squamata ‘Blue Swede’ which presents a spreading habit twice as wide as tall (1 metre high by 2 metres of spread). It offers blue-green foliage that will turn purple in autumn.

‘Holger’ also has a spreading habit to dress a bank or fill a rock garden, ranging from 1.2 to 2 metres wide. Its young shoots display bright pale yellow, borne on blue-green branches forming a striking contrast.

‘Tropical Blue’ is a smaller juniper, reaching 40 cm in height with a 1.5-metre spread. It naturally forms a low and dense carpet. It is notable for its steel-blue foliage, with tones even more pronounced in cold winter weather.

Let us also mention ‘Golden Flame’, more imposing at 1.70 metres in height for a 2.60-metre spread. Its foliage comprised of blue-silver needles contrasts with the young shoots of cream-yellow. It is particularly frost hardy (down to -30°C).

Juniperus squamata ‘Golden Flame’

Common junipers - Juniperus communis

Common junipers can take a variety of silhouettes: shrubby, upright, columnar, but also spreading. These are obviously the ones that interest us here. They’re hardy, easy-to-grow conifers that tolerate full sun as well as poor, occasionally dry and calcareous soils. Hard-wearing, all-terrain plants for ornamenting a slope.

This is the case with ‘Repanda’, with its prostrate silhouette so dense that it prevents adventive weeds from taking hold. Expect about 30 cm tall with a 2 metres spread after a few years.

‘Goldschatz’ does not exceed about 20 cm in height with a spread of 1.2 metres. This groundcover will brighten neglected areas of the garden, with its green-grey foliage revealing new golden shoots.

As its name suggests, ‘Green Carpet’ will form a handsome carpet of vegetation, thanks to its prostrate silhouette reaching 2 metres wide and under 50 cm high. These long green shoots with silvery reflections will take on bluish-purple hues in winter.

Juniperus communis ‘Goldschatz’

Pfitzer junipers - Juniperus pfitzeriana

Les Juniperus pfitzeriana reveal a spreading, graceful habit, often wider than tall. They are ideal groundcovers for ornamenting a slope, not least as they are highly adaptable. Like other members of their group, poor, calcareous soils and sometimes dry conditions do not scare them. They also have good frost resistance if the soil does not become waterlogged in winter. Melliferous, they are also conifers that will please insects and prove decorative thanks to their colourful fruiting, appreciated by birds.

‘Old Gold’ produces fine and supple foliage, golden-yellow at the base and bright at the tips. It takes on bronze reflections in winter. In terms of dimensions, expect about 1 metre in height with a spread of over 2 metres.

‘Goldkissen’ is just as interesting, with its low and very spreading silhouette, capable of reaching 2.5 metres in width by 50 cm in height. Its non-spiky foliage has a green base, enriched by golden-yellow hues.

‘Glauca’ is an imposing juniper, with a 3-metre spread for about half its height, capable of colonising large slopes. It features a spreading silhouette, with arching branches. Its fine and supple foliage displays a pretty bluish-grey.

Juniperus pfitzeriana ‘Glauca'</caption]

Savine junipers - Juniperus sabina

Juniperus sabina are junipers with a spreading and creeping habit, with foliage that is very dense, but not prickly. They will readily cascade down slopes, covering them year-round. As easy to grow as other junipers, they are perfectly hardy, withstanding wind, drought and altitude. A boon for the mountain gardens with steep slopes. They are able to grow in poor, dry and calcareous soil, requiring only good drainage. Plant them in full sun or partial shade.

‘Rockery Gem’ is a sabina juniper with glaucous-green foliage with bluish reflections. Over the years, it will reach a height of 70 cm with a 2-metre spread.

‘Variegata’ stands out with its variegated foliage, green maculate with white and yellow markings, which helps to bring light to the most inhospitable areas. Its spreading silhouette is twice as wide as tall: expect 60 cm in height and 1.2 metres in spread.

Cite également ‘Tam No Blight’, which has the same dimensions. This groundcover produces blue-green foliage that is very decorative.

Finally, let’s talk about ‘Tamariscifolia’, a sabina juniper with tamaris leaves that rewards us with a low and spreading habit. Its dimensions will be 80 cm in height by 2 metres in spread. Its branches form horizontal tiers that are well covering, coated with thick foliage in a green-silvery hue with bluish reflections.

Juniperus sabina ‘Tam No Blight’

Other interesting junipers for covering a slope.

This list is, of course, not exhaustive. Let us also mention the Juniperus procumbens ‘Nana’, which forms a large thorny carpet that hugs the contours of the ground. It has apple-green foliage turning bluish (30 cm in height with a 1.5 m spread).

Let us also mention some hybrids that form excellent groundcovers, such as the Juniperus chinensis ‘Expansa Variegata’ (50–60 cm in height with a spread of 1.5 m) or ‘Kuriwao Gold’ (2 m in height with a 3 m spread).

Juniperus procumbens ‘Nana’