Libertia sessiliflora Caerulescens

Libertia caerulescens, now renamed Libertia sessiliflora var. Caerulescens, is a small Chilean perennial which is still rare in cultivation, with an exotic appearance but which is relatively hardy. Related to irises, it is grown for the beauty of its spring flowers, in dense panicles of pale blue-mauve flowers enhanced by orange stamens. They bloom above a tuft of fine, bright green leaves, which are decorative even in winter.  It prefers well-drained, non-calcareous soils as well as a humid and wet climate throughout the year.

Libertia sessiliflora Caerulescens is a botanical species native to coastal areas of Chile. It belongs to the Iridaceae family. This upright clump-forming perennial averages 35 cm (14in) in height and 40 cm (16in) in width. Anchored on a stump with short rhizomes, it forms a dense tuft, slightly stiff, slightly spreading, evergreen in winter. In May, thin floral stems appear among the leaves, which are a brown-grey colour, bearing at their tips panicles filled with numerous clusters of small flowers with three petals and three sepals in a light blue-mauve colour. The centre of the corolla is filled with prominent stamens with mauve filaments and orange anthers. The plant then produces an abundance of oval grey capsules containing round seeds that germinate easily. It develops stiff, linear leaves, 30 to 40 cm (12 to 16in) long and 1 cm (0.5in) wide, with parallel veins and a bright green colour. This Libertia seems capable of withstanding short frosts of around -10°C (14°F) in well-drained soil.

Still very rarely planted in gardens, this charming Chilean Libertia with blue flowers deserves to be acclimatised in our gardens. It will thrive in damp but well-drained, rather humus-rich soil, in sunny or semi-shaded positions. It is an extremely refined collector's plant that deserves a prime location. It pairs well with Sisyrinchium, Crocosmia, Liatris, or even toad lilies (Tricyrtis hirta). This perennial will be appreciated in damp rockeries and borders.