Juniperus horizontalis Wiltonii

Juniperus horizontalis 'Wiltonii' is an elegant, discreet creeping juniper, as well as a dense and effective ground cover against adventives and unaffected by difficult conditions. With a well-balanced spreading habit, it forms over time a superb light grey-blue carpet that your hand will wander on: its fine-textured foliage is soft to the touch and leaves a balsamic resin scent on your fingers. In the cold, the carpet enriches itself with beautiful purple to violet reflections, becoming a central element for a flowerless private garden in winter. Vigorous and extremely hardy, this conifer is perfect for dressing a large slope, a rockery, or even in a container. It is also appreciated by bonsai enthusiasts. Give it full sun and a well-drained soil, even poor, occasionally dry and calcareous.

Juniperus horizontalis is an evergreen and prostrate conifer belonging to the cypress family, which includes similar species such as cypresses and Chamaecyparis. It is native to the northern regions of North America, which explains its excellent hardiness. In its natural environment, it has a prostrate, very spreading habit, reaching a thickness of 45cm (17.7in) and a spread of 2 to 4m (6ft 7in to 13ft 1in). This species appreciates cool climates, poor, sandy and/or calcareous soils, and is not afraid of arid conditions.

The 'Wiltonii' juniper is one of the many cultivars derived from this robust species. After 10 years, it forms a prostrate shrub with a very spreading habit, measuring 15 to 25cm (5.9 to 9.8in) in height and 1.20m (3ft 11in) in spread. It grows quite slowly when young, then its growth accelerates with age. An adult specimen will measure about 20-30cm (7.9-11.8in) in height and 2.50m (8ft 2in) in diameter, or even more. The spreading branches can root, so a single plant can eventually cover a large area. Its foliage consists of juvenile leaves that have a scale-like appearance but are not prickly. These small, tightly packed juvenile leaves emit a resinous and aromatic odour when rubbed. From spring to summer, the foliage takes on a soft grey-green colour with a hint of blue, gradually turning a beautiful, somewhat indescribable, purplish hue in winter. Junipers have a shallow root system that makes them fragile when transplanting, vulnerable to strong winds, and difficult to associate with perennials.

The creeping juniper 'Wiltonii' is an extraordinary conifer, very undemanding, that conquers even the most challenging areas of the garden as long as they are sunny. It will be adopted without reservation in a dry garden, on a large slope, among rocks, above a wall or low wall, or near a pool, as it goes well with geometric lines and masonry structures. It can also be planted near a water feature, cascading down a rocky scree. It also adapts very well to container cultivation. The real graphic qualities of conifers naturally impose themselves in the design of a contemporary garden, which prefers the aesthetics of shapes, silhouettes, and textures to the dance of blooms. These plants, with their reassuring permanence, structurally define a bed, mark pathways, border terraces, easily substituting for the strong presence of trimmed boxwood. They go well with heathers, tousled grasses like marram grass, with a very complementary temperament. The key is to play with volumes and colours.