Andropogon ternarius

Andropogon ternarius, known as the Splitbeard Bluestem, is one of those North American grasses that deserve more attention in our gardens. It reveals itself in late summer or early autumn, when it forms a bristly clump with shades of bronze and copper, adorned with silvery white feathery spikes that catch the light. This vegetation remains decorative in autumn and winter. Hardy in every sense of the word, this wild and charming grass is particularly recommended in poor and dry soils in summer, in full sun.

Andropogon ternarius belongs to the large family of Poaceae. It is an American grass that is frequently found in the company of Schizachyrium scoparium in the central and southeastern regions of the United States. There, it is found in plains, meadows, savannahs, open forests, and roadside areas, often on well-drained sandy or gravelly soils. The plant forms a dense, erect clump measuring between 60 cm (24in) and 1.20 m (4ft) in height and 30 to 40 cm (12 to 16in) in width. The stems, or culms, are bluish in colour. In spring and summer, the slender ribbon-like leaves are bluish green, sometimes tinged with violet. From August onwards, the foliage turns bronze, rust, and then copper. The flowering occurs from August to September, depending on the climate. The stems bear multiple feathery spikes divided into two in their upper half, about 2.5 cm (1in) long, surrounded by yellow bracts. These spikes, with a reddish-brown colour, are adorned with long silver hairs at maturity, once the seeds are ripe.

Andropogon ternarius is resistant to everything except heavy and waterlogged soils, and as such, it is very useful in dry gardens, or in poor or sandy areas. Like many American grasses, it is perfect for adding colour and height to flower beds, even late in the season. Nature garden enthusiasts will also appreciate it, as its dense foliage provides a nesting site for certain birds that also collect the silky spikes to build their nests. It naturally associates with Muhlenbergia capillaris and Schizachyrium, as well as nepetas, shrubby salvias, and wormwoods. For a contrast of forms, it can be paired with mulleins or hollyhocks.