Libertia formosa

Libertia formosa, also known as the Chilean Iris, is a perennial rhizomatous plant that is highly decorative due to its evergreen foliage forming a dense cushion, and its remarkably abundant cream-white spring flowers.  Its growth is quite variable depending on the conditions, and this Libertia is also the most tolerant species to cold. It makes a big impact on the banks of a pond, as well as along a path where its exotic appearance does not go unnoticed.

Libertia formosa (synonym Libertia chilensis) belongs to the iris family. It is a species native to the mainland of Chile, also present in Argentina. In nature, the plant grows in rather humid places such as meadows, riverbanks, lake shores, swamps, etc. Its stump can withstand temperatures as low as -10 or -12 degrees Celsius (14 or 10.4°F) , as well as dry periods of no more than one month. It appreciates humid atmospheres.

This Chilean Iris is a herbaceous perennial plant that forms an elegant tuft measuring between 60 cm (24in) and 1.20 m (4ft) in height, depending on the growing conditions. Its rhizomatous stump extends about 60 cm (24in) wide. The foliage consists of rigid, leathery leaves, measuring 30 to 45 cm (12 to 18in) long and 0.6 to 1.2 cm (0.5 to 1in) wide, which are light green with bronze reflections and evergreen in winter. Flowering occurs in May-June. Stiff and tall flower stems emerge from the foliage, bearing paniculate cream-white flowers with 3 petals, each flower measuring about 3 cm (1in) in diameter. The flower stems appear in great numbers on older stumps, sometimes covering the foliage under favourable conditions. This slightly scented flower is visited by pollinating insects.

This relative of irises prefers slightly acidic, sandy and humus-rich soils, which are well-drained, moderately moist to moderately dry. Quite tolerant, this species is particularly suited to seaside gardens. Libertia formosa pairs well with Virginia Spiderwort (Tradescantia), Daylilies, or Crocosmias, for example, beautiful perennials that appreciate similar growing conditions.