7 blue conifers for rock gardens

Chamaecyparis pisifera 'Blue Moon' – Sawara Cypress, a globe-shaped shrub with soft blue-silver foliage.

The Chamaecyparis pisifera ‘Blue Moon’ or Sawara Cypress offers an elegant, ball-shaped habit, which, in addition to being graceful, saves us from having to prune it.

Its evergreen, fine foliage is an intense silvery-blue. This slow-growing dwarf conifer grows 2–3 cm per year and forms a shrub 80 cm high by 80 cm wide in maturity.

The very flexible, dense and slightly trailing shoots bear light-green foliage when young, which becomes darker, scaly and pointed in maturity.

If it is silver-blue in full sun, it becomes bluish-green in shade.

Hardy, this conifer thrives in sun or partial shade, in cool, well-drained, lime-free soil.

In a rock garden, play with contrasts of form and pair the rounded habit of Sawara Cypress with columnar-habit conifers such as Chamaecyparis lawsoniana ‘Elwood’s Gold’—Lawson Cypress, which has a pyramidal habit, with the variety Chamaecyparis pisifera ‘Baby Blue’ or with a conical form, such as the dwarf Swiss pine – Pinus cembra ‘Compacta Glauca’.

Scaly juniper - Juniperus squamata 'Tropical Blue', a carpet-like habit and steel-blue foliage.

With its creeping habit and steel-blue foliage, the scaly juniper – Juniperus squamata ‘Tropical Blue’ adds an unusual touch to a rock garden. It spreads to a width of up to 1.5 metres and does not exceed a height of 40 cm. The blue colour of its foliage intensifies in winter as the cold sets in. Its dense shoots are clad with small pointed leaves that are imbricate, giving it a bristly appearance. Hardy to -29°C, it originates from the Himalayas and China. It prefers full sun but can also grow in partial shade. It should be planted in neutral to calcareous soil, not too dry but well-drained.

In a contemporary-style rock garden, pair this blue-coloured juniper with a Taxus baccata Fastigiata Robusta – Common fastigiate yew with dark-green foliage. The contrast between the colours, as well as between the juniper’s spreading habit and the yew’s upright habit, will create a striking effect.

Colorado blue spruce, Picea pungens 'Blue Pearl', a miniature blue conifer.

With its steel-blue foliage and very slow growth, the Colorado blue spruce – Picea pungens ‘Blue Pearl’, also known as the blue spruce, forms a small ball-shaped shrub, which evokes a hedgehog. When it reaches 50 cm high by 50 cm wide at maturity, it grows at a rate of 2.5 cm per year and reaches a size of only 30 cm after 10 years. This slow growth makes it a perfect conifer for a small rock garden. Its evergreen foliage consists of short, dense needles in an intense silvery-blue colour. Very hardy, it tolerates temperatures down to -29°C. Cultivate it in neutral to acidic soil, even calcareous, and in full sun.

To showcase it in a rock garden, pair it with other compact plants like it, such as the Veronica shrub ‘Emerald Green’, which also forms a globe-shaped evergreen shrub, or Berberis thunbergii ‘Tiny Gold’, whose green-yellow foliage will provide contrast to the blue of the dwarf spruce.

The Chamaecyparis lawsoniana 'Rimpelaar' – a dwarf Lawson's cypress, bluish-green glaucous shrub.

The Chamaecyparis lawsoniana ‘Rimpelaar’ – Lawson’s dwarf cypress also benefits from attractive features for a rock garden. Of a size a little taller than the others, it forms a dense, slightly irregular ball of 1.5 metres by 1.5 metres at maturity. However, slow-growing, it will reach dimensions of only 60 cm by 60 cm after 10 years. Its foliage takes on a bluish-green, grey-green colour and is soft to the touch. Its numerous slender shoots are thus adorned with scale-like needles, which are not prickly. The blue needles, when young, take on a greyed tint with age. This conifer thrives in full sun, in fertile soil that is not too dry.

In a rock garden, pair this dwarf Lawson cypress with airy grasses, such as the Stipa tenuifolia – Angel Hair Pony Tails or the Miscanthus sinensis ‘Aperitiv’ (Aperitif) – Chinese reed to bring lightness to the bed.

Dwarf spruce - Picea mariorika Machala, soft to the touch foliage.

With bluish-silvery foliage, the dwarf spruce or Picea mariorika ‘Machala’ displays a globular silhouette before taking on a pyramidal dome-shaped habit. The branches of this fluffy shrub resemble densely packed little brush-like tufts, formed of short, soft and aromatic needles. Pale blue shoots appear on mature foliage that is blue-grey in colour. Slow-growing, this small conifer reaches a height of 80 cm with a spread of 1.2 m. Easy to grow, it enjoys a sunny position, as well as moist, well-drained soil. It tolerates frost very well as it is hardy down to -34°C.

In a rock garden, you can pair its fluffy silhouette with heathers of various colours or play with shapes and volumes by planting dwarf conifers with erect or creeping habit beside it.

The scaly juniper - Juniperus squamata 'Blue Carpet', a dwarf and creeping conifer.

With dense, intense blue-silver foliage, the scaly juniper – Juniperus squamata ‘Blue Carpet’ fits beautifully into a rock garden. After a few years, it forms a bush with a spreading habit, 40 cm high with a 1.5 metre spread. Its branches, feathery in appearance, bear small scale-like leaves very tightly arranged. It features reddish-brown bark and bears black berries, especially on female plants.

This scaly juniper fits into a rock garden alongside other dwarf conifers of varying shapes and colours, as well as heathers.

Abies koreana Kohout's Icebreaker® - dwarf Korean fir for a large rock garden

Abies koreana ‘Kohout’s Icebreaker’® – Dwarf Korean fir is a dwarf variety of Korean fir. It is distinguished by its rounded habit and green foliage, which becomes blue with age. Its young leaves have a white reverse, which makes the shrub particularly bright. It bears small, upright cones with a striking powdery blue-violet colour. Slow-growing, it features a pyramidal habit and reaches 2 metres tall by 1 metre wide at maturity. Cool, well-drained soil, a sunny exposure that is not scorching or partial shade, are the conditions for it to thrive.

In a large rockery, you can pair this dwarf Korean fir with other conifers of unusual shapes such as the Chamaecyparis pisifera ‘Blue Moon’ – Sawara Cypress.