Chamaecyparis thyoides Blue Rock

Chamaecyparis thyoides Blue Rock, also known as Atlantic White Cedar, is a very recent dwarf conifer with sumptuous foliage. It forms a compact ball with very fine and dense foliage, initially green-blue, turning to purple in winter. It grows very slowly, not exceeding 1.50 m (4 ft 11 in) in all directions at maturity. While it is perfect in rockeries and small spaces, this conifer also adapts remarkably well to container cultivation. It prefers a sunny or semi-shaded exposure and soil that remains moist, light and well-drained and is humus-rich and acidic.

Chamaecyparis thyoides is a very hardy species native to eastern North America, specifically from the coast of Maine to Florida. It belongs to the cypress family and is also called Atlantic White Cypress. In its natural environment, it can reach a height of 18 m (59 ft 1 in) and has a narrow conical habit. It has given rise to many cultivars with very variable habits and foliage.

The Blue Rock variety was introduced in 2012 by a Dutch nursery. It originated from a mutation that appeared on a branch of a specimen of Chamaecyparis thyoides 'Top Point', which was then propagated by cuttings. After 10 years, it forms a beautiful rounded bush, measuring 40 to 50 cm (15.7 to 19.7 in) in height, and 30 to 40 cm (11.8 to 15.7 in) in width. It could eventually reach a height of 1m (3 ft 4 in) to 1.5m (4 ft 11 in) after many years of cultivation. It grows slowly, at a rate of 4 to 5 cm (1.6 to 2 in) per year. This small conifer retains its juvenile foliage in the form of very short needles with blue highlights, without developing the scale-like leaves of the species. Its fine grey-green twigs are grouped in very small irregularly arranged fans on the branches. The interior of the ball consists of bare grey-green twigs. The foliage takes on magnificent plum to violet highlights in winter.

Chamaecyparis thyoides Blue Rock is a small, hardy and original conifer that will be perfect in the garden with its changing and beautifully coloured foliage. It is ideal for planting in pots on the terrace, and of course in rockeries. With its very slow growth and its round silhouette, which requires no pruning, it will work well alongside taller varieties with columnar, pyramidal or narrow conical habits. The architectural qualities of dwarf conifers naturally impose themselves in the design of a contemporary garden, which prefers the aesthetics of shapes, silhouettes and textures to flowers. These plants structurally anchor a bed, mark the paths and border the terrace, easily replacing the strong presence of trimmed boxwood. They serve as a setting for small roses, peonies, or airy grasses with very complementary forms. They can also be associated with ground cover plants such as aubrietas and cerastiums, as well as flowering shrubs. The key is to play with volumes and colours.