Cornus kousa Blue Shadow - Flowering Dogwood

The Cornus kousa 'Blue Shadow' is a renowned selection for having the bluest foliage among all Japanese Dogwoods. Its large leaves give it a particular grace and turn splendid shades of red and purple in autumn. The dense vegetation provides a beautiful backdrop to the equally sumptuous flowering, which opens into large white stars in spring for several weeks. It is followed by beautiful round berries in a pink-red colour, which ripen during a long, hot summer. Very hardy and easier to grow than its cousin Cornus florida, this beautiful shrub deserves a place in the garden, whether as a standalone or in a mixed border.

The Dogwood belongs to the small family Cornaceae, which, after several revisions in botanical classification, now only consists of the genera Cornus and Alangium. Cornus kousa is a tree with small stature or a large shrub, native to Japan, China, and Korea. Its architectural silhouette, formed by usually tiered and horizontal branches, gives it a Japanese appearance. The botanical species has given rise to several horticultural varieties, the result of the work of breeders.

'Blue Shadow' is a cultivar obtained by American breeder Don Shadow and introduced to the market by the Poly Hill Arboretum (Massachusetts, USA). It is easily recognisable by its very blue-green foliage that contrasts beautifully with the brown wood. Growing rather slowly, this shrub takes on a tabular habit, almost as wide as it is tall, and reaches approximately 3 m (10ft) in height and 2.50 m (8ft) in spread after ten years of cultivation. Its growth continues to reach a height of around 5 m (16ft), or even more, at maturity. Flowering occurs in May-June, well highlighted by the somewhat dark blue foliage, on which the white flower heads stand out. These are clusters of small true flowers, green in colour, surrounded by four pointed bracts forming a star, and are often mistaken for flowers, although they are transformed leaves. Measuring a good ten centimetres in diameter, the flowerheads seem to be resting on the foliage, like a colony of immaculate butterflies. These numerous, architectural and airy flower heads, dominating the slightly drooping blue foliage, create a magical spectacle in spring. The flowers are followed by fruits with a diameter of 2.5 cm (1in), in dark pink to red colour, reminiscent of strawberries in colour and blackberries in appearance. The higher the summer temperatures, the more generous the fruiting. The fruits are edible, fleshy, and have a sweet taste, although not particularly interesting in terms of flavour, but they are quite decorative at the end of the season. In autumn, the foliage takes on superb purple or dark red colours.

The Cornus kousa 'Blue Shadow' thrives in continental climates, with marked summers and winters, but performs well in milder zones too. In hot regions, it should be planted in a sheltered spot to protect it from the scorching sun. Its aesthetic justifies planting it as a standalone, but since it grows quite slowly, it may be wise to integrate it into a border to achieve a more interesting scene more quickly, while still allowing enough space for its development. Surround it with small-sized shrubs that will not hinder its growth, such as the Chinese Azalea Nabucco, whose trumpet-shaped bright red flowers will form a superb contrast with the white bracts of your Dogwood. The Kalmia latifolia Ewa, a Mountain Laurel with astonishing ribbed flower buds opening into pale pink flowers, will also be a good companion. And to create a classy autumn scene, plant a tree in the background that turns yellow or orange, such as the Japanese Katsura Tree, nicknamed the caramel tree for the delicious scent it produces in autumn.