Culture
Best grown in rich, well-drained soils in part shade. Likes moist boggy areas. Prefers part shade with 1-2 hours of morning or evening sun in cool summer climates with moderately cold winters. Best performance occurs in USDA Zones 3-7 (Zone 8 if plants are given additional shade). Spreads by creeping rhizomes. May be propagated by seed or division. Never dig plants in the wild, not only because of their rarity but also because they transplant very poorly.
Noteworthy Characteristics
Cypripedium kentuckiense, commonly called southern lady's slipper or Kentucky lady's slipper, is a clump-forming terrestrial orchid with a thick creeping rhizome and hairy stem. It typically grows to 18-30” tall and produces the largest flowers of any known lady’s slipper. It is rarely found in the wild, and currently carries the Center for Plant Conservation Global Rank of “G3 Vulnerable” meaning that it is at moderate risk of extinction due to restricted range, few remaining populations (often 80 or fewer), and recent widespread population declines. Fewer than 3,000 plants may still exist in the wild. It is native to damp low woodlands, rich alluvial floodplains, moist woodland slopes, and along streams in widely-scattered areas from Virginia to Kentucky to Alabama and further west to eastern Oklahoma and eastern Texas. Notwithstanding the geography of its native range, this orchid can be successfully grown as far north as Vermont and central Minnesota with the protection of a quality winter mulch.
Each plant typically grows to 18-30" tall on a single pubescent stem clad with 2-9 (on average 5) pleated, parallel-veined, broad-ovate to ovate-lanceolate, leaves (each to 7" long) which are evenly arranged along the stem. Each leaf is sheathed to the stem at the leaf base. The stem is topped by a single flower which blooms in spring (late April-June). Each flower (to 5” across) features a large, showy, cream to pale yellow pouch (inflated lower petal known as the lip) which is the size of a chicken egg, with two downward twisting, lateral, mottled greenish-purple petals (to 4" long and 1/4" wide) and three wavy-edged sepals which are a contrasting and showy purplish-brown. Fruit is an ellipsoid capsule (to 2" long) with minute but abundant seeds which matures in fall.
Rarely found in the wild. Plants transplant poorly and should never be dug. Very few orchids survive transplanting from the wild to a home landscape.
Genus name comes from the Greek words kupris meaning Aphrodite or from kupros meaning Cypress where Aphrodite was born and pedilon meaning shoe in reference to the purported resemblance of the flower to Aphrodite's slipper.
Specific epithet is in reference to the State of Kentucky where this orchid grows.
The flower purportedly resembles a pale yellow lady’s slipper hence the common name.
Problems
No serious insect or disease problems.
Uses
Moist woodland areas. This rare plant will be very difficult to obtain in commerce.