Cypripedium kentuckiense

Cypripedium kentuckiense, also known as the Kentucky Lady's Slipper, is a large and beautiful botanical species native to the southern United States. This terrestrial orchid is fully hardy and tolerates hot summers well, but successful cultivation requires a good understanding of its soil requirements. Its large flowers consist of long purple petals washed with green and yellow, crowning a swollen slipper-shaped lip, white tinged with yellow. To acclimate it to the garden, provide this Lady's Slipper with a shaded or semi-shaded exposure as well as a sandy and humus-rich soil, slightly acidic, remaining slightly moist but not waterlogged.

Cypripedium kentuckiense is the Lady's Slipper with the largest flowers. They can easily reach over 12cm (5in) in diameter when not fully open. This species is found in the deep gorges of mountain ranges in the central part of the United States. It is present, discontinuously, in Tennessee, Kentucky, Missouri, Texas, and Ohio. The plant grows on acidic and greasy soils. Such soil is characterized by the presence of coarse sand, gravel, high porosity, intense biological activity, a humus cover, and the presence of clay and iron. This helps to better understand the conditions that will satisfy this orchid.

The Kentucky Lady's Slipper develops from a fleshy stump from which light green, ovate elliptical leaves emerge in early spring, 12cm (5in) long, sessile and embracing, with strongly impressed parallel veins. The stump slightly suckers, allowing it to eventually form beautiful colonies. In late spring, around May-June and for about two weeks, the plants produce beautiful hairy flower stalks, sometimes rising up to 80cm (32in) or 1m (3ft) from the ground. Each stalk bears a solitary flower. The flower is formed by slender, twisted sepals and petals, purple-brown in color, speckled with aubergine and green, and a large ventral lip ranging from ivory white to pale yellow. Each plant is generally uniflorous. The above-ground vegetation is absent in winter.

Cypripedium kentuckiense thrives on the edge of forests, in partial shade, in suitable soil. Plant it in shade, in a cool rockery, between rocks, or on the edge of a fresh understory, alongside Arisaema, Calanthe, Paris, Bletilla, and ferns. It will also thrive in a container, an unheated greenhouse, and in a non-calcareous substrate.

Handle your orchids with care when you receive them: these plants produce few roots and are delicate!