Artemisia ludoviciana Silver Queen - Armoise de Louisiane, Armoise argentée

Artemisia ludoviciana ‘Silver Queen’, called Louisiana sagebrush or silver sage, is distinguished by its almost white foliage, brighter than that of the wild species. This perennial fairly quickly forms a flexible clump that brightens borders from spring onwards. Its summer flowering is discreet: it is planted above all for the colour and texture of its leaves. It is a good variety for dry gardens and sunny borders. Its foliage links the more colourful blooms in the garden.

This sagebrush belongs to the Asteraceae family, like daisies and yarrows. Artemisia ludoviciana is a perennial plant native to a large part of America, from Canada to Mexico, Guatemala and El Salvador. It grows particularly in dry meadows, open ground, on banks, in stony soils and disturbed areas. Its vegetation resprouts each year from underground rootstocks. 'Silver Queen' forms an upright, fairly loose clump, 60 to 90 cm tall. It reaches 50 to 80 cm in width in a few years, but can spread further when its rootstocks encounter no obstacle. Its growth is fairly rapid. Young shoots appear in spring, producing straight stems covered with leaves. These are long, narrow and lanceolate, sometimes entire, sometimes coarsely dentate. Their surface is covered with fine hairs that give them a uniform grey-white colour and a soft feel. When crushed, they release an aromatic scent characteristic of sagebrushes. The foliage is deciduous to semi-evergreen depending on the severity of the winter: it disappears in cold regions but may partially persist in mild climates. Between June and August, the plant produces upright panicles of small yellowish or cream heads. These flowers, lacking large decorative petals, blend into the foliage and are of little ornamental interest. Early removal of them keeps the clump neater and encourages leaf development. This plant tolerates down to -18°C, poor soils and drought once established. Its rootstocks produce new shoots at a distance from the original clump, so it will be necessary to monitor their spread in small borders. 
The species name ludoviciana refers to the former territory of Louisiana, which once covered a large part of central North America. Several indigenous peoples of North America have used different wild forms of this sagebrush as an aromatic plant and in traditional practices.

This sagebrush is planted on dry slopes, in scree gardens and naturalistic borders. Its silver foliage forms broad carpets and highlights small shrubs for dry soil. It is best to plant it away from their rootstocks or contain its rootstocks. It can be paired with Ceratostigma willmottianum 'Forest Blue', compact and floriferous, with the shrubby sage 'Royal Bumble', or with Teucrium fruticans 'Selection Erecta', well suited to poor soils. A shrubby cinquefoil such as 'Lemon Meringue' will brighten the whole with its long pale yellow summer flowering.